Though phototherapy is a very successful, safe and cost effective treatment option, its use as a common therapy for psoriasis is declining. This series was created to offer readers practical advice on how and when to use phototherapy.
Although the beneficial properties of phototherapy are well known, they are countered by certain side effects, including increased risk of skin cancer, photodamage and photosensitivity reactions. The balance between therapeutic effects and adverse effects is achieved through proper patient selection. This article focuses on patient selection for phototherapy in general, and more specific indications and contraindications for particular varieties of phototherapy, including psoralen ultraviolet A (PUVA), broadband ultraviolet B (BBUVB), narrowband ultraviolet B (NBUVB), the 308-nm excimer laser, and ultraviolet A1 (UVA1) phototherapy. General Considerations The indications for phototherapy in general are the starting point to determine which patients would be appropriate candidates for phototherapy. General considerations include characteristics of the patient’s disease such as percent body surface area (%BSA) that is involved; a large %BSA makes topical or localized treatment alone rather impractical. Other indications include disease that is seemingly resistant to other treatment modalities, disease that has demonstrated a response to phototherapy in the past, or improvement upon exposure to natural sunlight. There may be other systemic therapies available for the patient’s disease. However, if the patient has medical conditions that do not allow the use of these treatments or if the patient is unable to tolerate the side effects of systemic therapy, phototherapy should be considered. Patients need to be able to understand and comply with instructions, as extra ultraviolet (UV) exposure after phototherapy can result in severe burns and increase the amount of cumulative UV exposure. Additionally, the skin type of the patient has a role in determining which modality of phototherapy may be most effective. General Contraindications Underlying medical conditions such as some immunosuppressive states (for example, a liver transplant recipient), photodermatoses such as xeroderma pigmentosum and basal cell nevus syndrome, or systemic diseases with a photosensitive component such as systemic lupus erythematosus (SLE) or dermatomyositis, preclude the use of certain types of phototherapy. In other immunosuppressive states — for example, HIV positive patients or other photodermatosis such as polymorphous light eruption (PMLE)— phototherapy is not contraindicated and can be an effective therapy. Phototherapy is contraindicated in a patient with a history of melanoma. Phototherapy in a patient with a history of nonmelanoma skin cancers should only be considered if all other therapeutic options have been exhausted. A history of excess UV exposure, young age, skin types I and II, atypical nevi, and family history of nonmelanoma skin cancer or melanoma are relative contraindications to phototherapy and should prompt an open discussion with the patient about the benefits of phototherapy versus the increased risks of skin cancer. Other relative contraindications include current or previous treatment with ionizing radiation, arsenic, cyclosporine or systemic tacrolimus. Patients who are claustrophobic or unable to stand for minutes at a time are not candidates for booth phototherapy. Relative contraindications to phototherapy also include the inability to comply with a time-intensive treatment process that requires multiple trips to the office weekly. The out-of-pocket cost for phototherapy can be significant, especially when you factor in the cost of gas, parking, travel time, time away from work, co-pays for medications (psoralens) and co-pays for treatment. One solution to some of these limitations may be the use of a home light unit. Areas affected by disease will help determine if phototherapy is a potential therapy. Scalp and nail disease do not receive adequate UV exposure and will not respond to booth phototherapy. These are general guidelines. Phototherapy may be used with caution in rare patients with a contraindication if all other therapies have been exhausted and an open discussion about the risks and benefits of phototherapy are understood by both the patient and the physician. PUVA PUVA is commonly utilized in the treatment of psoriasis, vitiligo, mycosis fungoides, atopic dermatitis, lichen planus and chronic graft-versus-host disease. Indications for the use of PUVA include large BSA involvement, disease that is recalcitrant to other therapies (topical or UVB phototherapy), or particularly severe disease. Skin type also plays a role in patient selection; due to the longer wavelength of UVA, PUVA penetrates deeper and is often more effective in clearing psoriasis in darker skin types than other phototherapy modalities. Skin types I and II are at increased risk for photodamage, so PUVA should be considered as a second-line phototherapy option. The subtype of a particular disease can also play a factor. For example, stable generalized pustular psoriasis, pustulosis palmoplantaris and stable erythrodermic psoriasis are more responsive to PUVA than UVB.1 Unique considerations include a well established increased risk in both non-melanoma2 and melanoma skin cancers;3 therefore, a history of such cancers in a patient would preclude the use of PUVA. Use of PUVA in patients under the age of 10 is a relative contraindication because of the known long-term side effects of photodamage and increased carcinogenic risk. Psoralen is a pregnancy class C medication, and it is advised that patients who are pregnant or nursing not utilize PUVA as a mode of phototherapy. Those patients with decreased hepatic or renal function, which may slow the clearance of psoralens from the body, should be monitored closely and a dose adjustment should be considered. Especially with PUVA, patients need to be able to comprehend and comply with instructions to avoid extra ultraviolet (UV) exposure to both skin and eyes after phototherapy, as this can result in severe burns and increase the amount of cumulative UV exposure. An outdoor occupation may not be practical with PUVA therapy unless the patient’s treatment is at the end of the day. Most medications that cause a phototoxic reaction do so in conjunction with UVA. Patients’ medications need to be closely monitored for change and phototherapy dose adjustment made accordingly to avoid severe toxicity. The use of PUVA in patients with aphakia without correction with a UVA-blocking lens should only be considered if strict eye protection is used.4 The risk of skin cancer increases after greater than 200 PUVA treatments.5 The treating physician should keep a close account of the total lifetime number of PUVA treatments a patient has received and discuss therapy modifications. Genital lesions in male patients should not be treated with phototherapy due to an increase risk of skin cancer in this area.6 UVB Currently, UVB is a commonly utilized treatment for a plethora of dermatological conditions, including psoriasis, atopic dermatitis, vitiligo, pruritus, parapsoriasis and early stage mycosis fungoides, and polymorphous light eruption (PMLE). NBUVB is the standard of care, particularly in the treatment of psoriasis, as its selective wavelengths (311nm to 312nm) are more effective than BBUVB.7 Indications for phototherapy with UVB include patient preference in regard to the desire to avoid oral medications. UVB is safe for use in pregnant patients, those who are nursing, and those with underlying hepatic or renal insufficiency in which the use of psoralens would be relatively contraindicated. In patients with skin types I and II, NBUVB is a better phototherapy option than PUVA. UVB is safe for use in children as long as they are able to follow directions when in the light booth. Relative contraindications include the use of photosensitizing medications with an action spectrum in the UVB range, and a personal history of nonmelanoma skin cancer. PMLE, chronic actinic dermatitis, and solar urticaria are photodermatoses whose action spectrum may include the UVB wavelengths. The 308-nm Laser The 308-nm XTrac excimer laser system (PhotoMedex, Montgomeryville, PA) allows for a more focal delivery of NBUVB. It is currently FDA-approved for the treatment of psoriasis, but also demonstrates utility in the treatment of other cutaneous disorders such as vitiligo. Indications for the use of this laser include a smaller BSA to be treated, localized plaques that have proven resistant to topical therapy, and difficult-to-treat locations such as palms, soles and scalp. Additional benefits include the ability to deliver phototherapy to only the affected skin, sparing the unaffected skin from the side effects of increased carcinogenesis and photodamage. Tanning in the area of treatment is a side effect and may, for example in vitiligo, accentuate the appearance of the affected areas due to a greater contrast of the depigmented area and unaffected tanned skin. There are no absolute contraindications to the use of the excimer laser; the relative contraindications of UVB should be applied. UVA1 UVA1 is an effective treatment for atopic dermatitis, localized scleroderma and PMLE. Possible utility exists in the treatment of mycosis fungoides, urticaria pigmentosa, sclerodermatous graft versus host disease, and keloids.8 The skin type of the patient may have an impact on the selection of UVA1 as the phototherapy modality. A multi-center retrospective analysis by Tuchinda et al9 reviewed 92 cases in which UVA1 was utilized for the treatment of a variety of dermatologic conditions. It showed that lighter Fitzpatrick skin types (types I-III) tended to respond better as compared to darker skin types (types IV-VI). However, a recent study by Jacobe et al10 examined 101 patients receiving UVA1 treatment for a variety of conditions, with scleroderma and morphea being the most common, and demonstrated that improvement scores from UVA1 phototherapy and mean cumulative UVA1 doses were not significantly different among the Fitzpatrick skin types evaluated, concluding that UVA1 should be considered as a therapeutic option in more darkly pigmented patients. Although more studies are needed to clarify this point, UVA1 is an option for all skin types. The long-term impact of UVA1 phototherapy and risk of carcinogenesis is not clear. Mouse model studies have demonstrated that UVA1 does induce reactive oxygen species and cyclobutane pyrimidine dimers that are known to induce mutations.11 However, no longitudinal studies exist examining the incidence of skin cancer in patients receiving UVA1. With this preliminary evidence in mind, it may be wise to use the same precautions as with UVA and UVB. Conclusion Phototherapy is a safe option for the treatment of many dermatologic conditions. Although phototherapy can cause side effects, such as photodamage and increased risk of skin cancer, through proper patient selection, it is possible to limit the impact of these side effects. Dr. Holly Kerr is a Senior Staff physician at Henry Ford Heath System, Detroit, MI, with a particular interest in phototherapy. She also specializes in contact dermatitis and transplant dermatology. Meredith Price is a fourth year medical student at Wayne State University in Detroit, MI. Disclosures: Dr. Kerr and Ms. Price have no conflict of interest with any of the material discussed in this article.
Though phototherapy is a very successful, safe and cost effective treatment option, its use as a common therapy for psoriasis is declining. This series was created to offer readers practical advice on how and when to use phototherapy.
Although the beneficial properties of phototherapy are well known, they are countered by certain side effects, including increased risk of skin cancer, photodamage and photosensitivity reactions. The balance between therapeutic effects and adverse effects is achieved through proper patient selection. This article focuses on patient selection for phototherapy in general, and more specific indications and contraindications for particular varieties of phototherapy, including psoralen ultraviolet A (PUVA), broadband ultraviolet B (BBUVB), narrowband ultraviolet B (NBUVB), the 308-nm excimer laser, and ultraviolet A1 (UVA1) phototherapy. General Considerations The indications for phototherapy in general are the starting point to determine which patients would be appropriate candidates for phototherapy. General considerations include characteristics of the patient’s disease such as percent body surface area (%BSA) that is involved; a large %BSA makes topical or localized treatment alone rather impractical. Other indications include disease that is seemingly resistant to other treatment modalities, disease that has demonstrated a response to phototherapy in the past, or improvement upon exposure to natural sunlight. There may be other systemic therapies available for the patient’s disease. However, if the patient has medical conditions that do not allow the use of these treatments or if the patient is unable to tolerate the side effects of systemic therapy, phototherapy should be considered. Patients need to be able to understand and comply with instructions, as extra ultraviolet (UV) exposure after phototherapy can result in severe burns and increase the amount of cumulative UV exposure. Additionally, the skin type of the patient has a role in determining which modality of phototherapy may be most effective. General Contraindications Underlying medical conditions such as some immunosuppressive states (for example, a liver transplant recipient), photodermatoses such as xeroderma pigmentosum and basal cell nevus syndrome, or systemic diseases with a photosensitive component such as systemic lupus erythematosus (SLE) or dermatomyositis, preclude the use of certain types of phototherapy. In other immunosuppressive states — for example, HIV positive patients or other photodermatosis such as polymorphous light eruption (PMLE)— phototherapy is not contraindicated and can be an effective therapy. Phototherapy is contraindicated in a patient with a history of melanoma. Phototherapy in a patient with a history of nonmelanoma skin cancers should only be considered if all other therapeutic options have been exhausted. A history of excess UV exposure, young age, skin types I and II, atypical nevi, and family history of nonmelanoma skin cancer or melanoma are relative contraindications to phototherapy and should prompt an open discussion with the patient about the benefits of phototherapy versus the increased risks of skin cancer. Other relative contraindications include current or previous treatment with ionizing radiation, arsenic, cyclosporine or systemic tacrolimus. Patients who are claustrophobic or unable to stand for minutes at a time are not candidates for booth phototherapy. Relative contraindications to phototherapy also include the inability to comply with a time-intensive treatment process that requires multiple trips to the office weekly. The out-of-pocket cost for phototherapy can be significant, especially when you factor in the cost of gas, parking, travel time, time away from work, co-pays for medications (psoralens) and co-pays for treatment. One solution to some of these limitations may be the use of a home light unit. Areas affected by disease will help determine if phototherapy is a potential therapy. Scalp and nail disease do not receive adequate UV exposure and will not respond to booth phototherapy. These are general guidelines. Phototherapy may be used with caution in rare patients with a contraindication if all other therapies have been exhausted and an open discussion about the risks and benefits of phototherapy are understood by both the patient and the physician. PUVA PUVA is commonly utilized in the treatment of psoriasis, vitiligo, mycosis fungoides, atopic dermatitis, lichen planus and chronic graft-versus-host disease. Indications for the use of PUVA include large BSA involvement, disease that is recalcitrant to other therapies (topical or UVB phototherapy), or particularly severe disease. Skin type also plays a role in patient selection; due to the longer wavelength of UVA, PUVA penetrates deeper and is often more effective in clearing psoriasis in darker skin types than other phototherapy modalities. Skin types I and II are at increased risk for photodamage, so PUVA should be considered as a second-line phototherapy option. The subtype of a particular disease can also play a factor. For example, stable generalized pustular psoriasis, pustulosis palmoplantaris and stable erythrodermic psoriasis are more responsive to PUVA than UVB.1 Unique considerations include a well established increased risk in both non-melanoma2 and melanoma skin cancers;3 therefore, a history of such cancers in a patient would preclude the use of PUVA. Use of PUVA in patients under the age of 10 is a relative contraindication because of the known long-term side effects of photodamage and increased carcinogenic risk. Psoralen is a pregnancy class C medication, and it is advised that patients who are pregnant or nursing not utilize PUVA as a mode of phototherapy. Those patients with decreased hepatic or renal function, which may slow the clearance of psoralens from the body, should be monitored closely and a dose adjustment should be considered. Especially with PUVA, patients need to be able to comprehend and comply with instructions to avoid extra ultraviolet (UV) exposure to both skin and eyes after phototherapy, as this can result in severe burns and increase the amount of cumulative UV exposure. An outdoor occupation may not be practical with PUVA therapy unless the patient’s treatment is at the end of the day. Most medications that cause a phototoxic reaction do so in conjunction with UVA. Patients’ medications need to be closely monitored for change and phototherapy dose adjustment made accordingly to avoid severe toxicity. The use of PUVA in patients with aphakia without correction with a UVA-blocking lens should only be considered if strict eye protection is used.4 The risk of skin cancer increases after greater than 200 PUVA treatments.5 The treating physician should keep a close account of the total lifetime number of PUVA treatments a patient has received and discuss therapy modifications. Genital lesions in male patients should not be treated with phototherapy due to an increase risk of skin cancer in this area.6 UVB Currently, UVB is a commonly utilized treatment for a plethora of dermatological conditions, including psoriasis, atopic dermatitis, vitiligo, pruritus, parapsoriasis and early stage mycosis fungoides, and polymorphous light eruption (PMLE). NBUVB is the standard of care, particularly in the treatment of psoriasis, as its selective wavelengths (311nm to 312nm) are more effective than BBUVB.7 Indications for phototherapy with UVB include patient preference in regard to the desire to avoid oral medications. UVB is safe for use in pregnant patients, those who are nursing, and those with underlying hepatic or renal insufficiency in which the use of psoralens would be relatively contraindicated. In patients with skin types I and II, NBUVB is a better phototherapy option than PUVA. UVB is safe for use in children as long as they are able to follow directions when in the light booth. Relative contraindications include the use of photosensitizing medications with an action spectrum in the UVB range, and a personal history of nonmelanoma skin cancer. PMLE, chronic actinic dermatitis, and solar urticaria are photodermatoses whose action spectrum may include the UVB wavelengths. The 308-nm Laser The 308-nm XTrac excimer laser system (PhotoMedex, Montgomeryville, PA) allows for a more focal delivery of NBUVB. It is currently FDA-approved for the treatment of psoriasis, but also demonstrates utility in the treatment of other cutaneous disorders such as vitiligo. Indications for the use of this laser include a smaller BSA to be treated, localized plaques that have proven resistant to topical therapy, and difficult-to-treat locations such as palms, soles and scalp. Additional benefits include the ability to deliver phototherapy to only the affected skin, sparing the unaffected skin from the side effects of increased carcinogenesis and photodamage. Tanning in the area of treatment is a side effect and may, for example in vitiligo, accentuate the appearance of the affected areas due to a greater contrast of the depigmented area and unaffected tanned skin. There are no absolute contraindications to the use of the excimer laser; the relative contraindications of UVB should be applied. UVA1 UVA1 is an effective treatment for atopic dermatitis, localized scleroderma and PMLE. Possible utility exists in the treatment of mycosis fungoides, urticaria pigmentosa, sclerodermatous graft versus host disease, and keloids.8 The skin type of the patient may have an impact on the selection of UVA1 as the phototherapy modality. A multi-center retrospective analysis by Tuchinda et al9 reviewed 92 cases in which UVA1 was utilized for the treatment of a variety of dermatologic conditions. It showed that lighter Fitzpatrick skin types (types I-III) tended to respond better as compared to darker skin types (types IV-VI). However, a recent study by Jacobe et al10 examined 101 patients receiving UVA1 treatment for a variety of conditions, with scleroderma and morphea being the most common, and demonstrated that improvement scores from UVA1 phototherapy and mean cumulative UVA1 doses were not significantly different among the Fitzpatrick skin types evaluated, concluding that UVA1 should be considered as a therapeutic option in more darkly pigmented patients. Although more studies are needed to clarify this point, UVA1 is an option for all skin types. The long-term impact of UVA1 phototherapy and risk of carcinogenesis is not clear. Mouse model studies have demonstrated that UVA1 does induce reactive oxygen species and cyclobutane pyrimidine dimers that are known to induce mutations.11 However, no longitudinal studies exist examining the incidence of skin cancer in patients receiving UVA1. With this preliminary evidence in mind, it may be wise to use the same precautions as with UVA and UVB. Conclusion Phototherapy is a safe option for the treatment of many dermatologic conditions. Although phototherapy can cause side effects, such as photodamage and increased risk of skin cancer, through proper patient selection, it is possible to limit the impact of these side effects. Dr. Holly Kerr is a Senior Staff physician at Henry Ford Heath System, Detroit, MI, with a particular interest in phototherapy. She also specializes in contact dermatitis and transplant dermatology. Meredith Price is a fourth year medical student at Wayne State University in Detroit, MI. Disclosures: Dr. Kerr and Ms. Price have no conflict of interest with any of the material discussed in this article.
Though phototherapy is a very successful, safe and cost effective treatment option, its use as a common therapy for psoriasis is declining. This series was created to offer readers practical advice on how and when to use phototherapy.
Although the beneficial properties of phototherapy are well known, they are countered by certain side effects, including increased risk of skin cancer, photodamage and photosensitivity reactions. The balance between therapeutic effects and adverse effects is achieved through proper patient selection. This article focuses on patient selection for phototherapy in general, and more specific indications and contraindications for particular varieties of phototherapy, including psoralen ultraviolet A (PUVA), broadband ultraviolet B (BBUVB), narrowband ultraviolet B (NBUVB), the 308-nm excimer laser, and ultraviolet A1 (UVA1) phototherapy. General Considerations The indications for phototherapy in general are the starting point to determine which patients would be appropriate candidates for phototherapy. General considerations include characteristics of the patient’s disease such as percent body surface area (%BSA) that is involved; a large %BSA makes topical or localized treatment alone rather impractical. Other indications include disease that is seemingly resistant to other treatment modalities, disease that has demonstrated a response to phototherapy in the past, or improvement upon exposure to natural sunlight. There may be other systemic therapies available for the patient’s disease. However, if the patient has medical conditions that do not allow the use of these treatments or if the patient is unable to tolerate the side effects of systemic therapy, phototherapy should be considered. Patients need to be able to understand and comply with instructions, as extra ultraviolet (UV) exposure after phototherapy can result in severe burns and increase the amount of cumulative UV exposure. Additionally, the skin type of the patient has a role in determining which modality of phototherapy may be most effective. General Contraindications Underlying medical conditions such as some immunosuppressive states (for example, a liver transplant recipient), photodermatoses such as xeroderma pigmentosum and basal cell nevus syndrome, or systemic diseases with a photosensitive component such as systemic lupus erythematosus (SLE) or dermatomyositis, preclude the use of certain types of phototherapy. In other immunosuppressive states — for example, HIV positive patients or other photodermatosis such as polymorphous light eruption (PMLE)— phototherapy is not contraindicated and can be an effective therapy. Phototherapy is contraindicated in a patient with a history of melanoma. Phototherapy in a patient with a history of nonmelanoma skin cancers should only be considered if all other therapeutic options have been exhausted. A history of excess UV exposure, young age, skin types I and II, atypical nevi, and family history of nonmelanoma skin cancer or melanoma are relative contraindications to phototherapy and should prompt an open discussion with the patient about the benefits of phototherapy versus the increased risks of skin cancer. Other relative contraindications include current or previous treatment with ionizing radiation, arsenic, cyclosporine or systemic tacrolimus. Patients who are claustrophobic or unable to stand for minutes at a time are not candidates for booth phototherapy. Relative contraindications to phototherapy also include the inability to comply with a time-intensive treatment process that requires multiple trips to the office weekly. The out-of-pocket cost for phototherapy can be significant, especially when you factor in the cost of gas, parking, travel time, time away from work, co-pays for medications (psoralens) and co-pays for treatment. One solution to some of these limitations may be the use of a home light unit. Areas affected by disease will help determine if phototherapy is a potential therapy. Scalp and nail disease do not receive adequate UV exposure and will not respond to booth phototherapy. These are general guidelines. Phototherapy may be used with caution in rare patients with a contraindication if all other therapies have been exhausted and an open discussion about the risks and benefits of phototherapy are understood by both the patient and the physician. PUVA PUVA is commonly utilized in the treatment of psoriasis, vitiligo, mycosis fungoides, atopic dermatitis, lichen planus and chronic graft-versus-host disease. Indications for the use of PUVA include large BSA involvement, disease that is recalcitrant to other therapies (topical or UVB phototherapy), or particularly severe disease. Skin type also plays a role in patient selection; due to the longer wavelength of UVA, PUVA penetrates deeper and is often more effective in clearing psoriasis in darker skin types than other phototherapy modalities. Skin types I and II are at increased risk for photodamage, so PUVA should be considered as a second-line phototherapy option. The subtype of a particular disease can also play a factor. For example, stable generalized pustular psoriasis, pustulosis palmoplantaris and stable erythrodermic psoriasis are more responsive to PUVA than UVB.1 Unique considerations include a well established increased risk in both non-melanoma2 and melanoma skin cancers;3 therefore, a history of such cancers in a patient would preclude the use of PUVA. Use of PUVA in patients under the age of 10 is a relative contraindication because of the known long-term side effects of photodamage and increased carcinogenic risk. Psoralen is a pregnancy class C medication, and it is advised that patients who are pregnant or nursing not utilize PUVA as a mode of phototherapy. Those patients with decreased hepatic or renal function, which may slow the clearance of psoralens from the body, should be monitored closely and a dose adjustment should be considered. Especially with PUVA, patients need to be able to comprehend and comply with instructions to avoid extra ultraviolet (UV) exposure to both skin and eyes after phototherapy, as this can result in severe burns and increase the amount of cumulative UV exposure. An outdoor occupation may not be practical with PUVA therapy unless the patient’s treatment is at the end of the day. Most medications that cause a phototoxic reaction do so in conjunction with UVA. Patients’ medications need to be closely monitored for change and phototherapy dose adjustment made accordingly to avoid severe toxicity. The use of PUVA in patients with aphakia without correction with a UVA-blocking lens should only be considered if strict eye protection is used.4 The risk of skin cancer increases after greater than 200 PUVA treatments.5 The treating physician should keep a close account of the total lifetime number of PUVA treatments a patient has received and discuss therapy modifications. Genital lesions in male patients should not be treated with phototherapy due to an increase risk of skin cancer in this area.6 UVB Currently, UVB is a commonly utilized treatment for a plethora of dermatological conditions, including psoriasis, atopic dermatitis, vitiligo, pruritus, parapsoriasis and early stage mycosis fungoides, and polymorphous light eruption (PMLE). NBUVB is the standard of care, particularly in the treatment of psoriasis, as its selective wavelengths (311nm to 312nm) are more effective than BBUVB.7 Indications for phototherapy with UVB include patient preference in regard to the desire to avoid oral medications. UVB is safe for use in pregnant patients, those who are nursing, and those with underlying hepatic or renal insufficiency in which the use of psoralens would be relatively contraindicated. In patients with skin types I and II, NBUVB is a better phototherapy option than PUVA. UVB is safe for use in children as long as they are able to follow directions when in the light booth. Relative contraindications include the use of photosensitizing medications with an action spectrum in the UVB range, and a personal history of nonmelanoma skin cancer. PMLE, chronic actinic dermatitis, and solar urticaria are photodermatoses whose action spectrum may include the UVB wavelengths. The 308-nm Laser The 308-nm XTrac excimer laser system (PhotoMedex, Montgomeryville, PA) allows for a more focal delivery of NBUVB. It is currently FDA-approved for the treatment of psoriasis, but also demonstrates utility in the treatment of other cutaneous disorders such as vitiligo. Indications for the use of this laser include a smaller BSA to be treated, localized plaques that have proven resistant to topical therapy, and difficult-to-treat locations such as palms, soles and scalp. Additional benefits include the ability to deliver phototherapy to only the affected skin, sparing the unaffected skin from the side effects of increased carcinogenesis and photodamage. Tanning in the area of treatment is a side effect and may, for example in vitiligo, accentuate the appearance of the affected areas due to a greater contrast of the depigmented area and unaffected tanned skin. There are no absolute contraindications to the use of the excimer laser; the relative contraindications of UVB should be applied. UVA1 UVA1 is an effective treatment for atopic dermatitis, localized scleroderma and PMLE. Possible utility exists in the treatment of mycosis fungoides, urticaria pigmentosa, sclerodermatous graft versus host disease, and keloids.8 The skin type of the patient may have an impact on the selection of UVA1 as the phototherapy modality. A multi-center retrospective analysis by Tuchinda et al9 reviewed 92 cases in which UVA1 was utilized for the treatment of a variety of dermatologic conditions. It showed that lighter Fitzpatrick skin types (types I-III) tended to respond better as compared to darker skin types (types IV-VI). However, a recent study by Jacobe et al10 examined 101 patients receiving UVA1 treatment for a variety of conditions, with scleroderma and morphea being the most common, and demonstrated that improvement scores from UVA1 phototherapy and mean cumulative UVA1 doses were not significantly different among the Fitzpatrick skin types evaluated, concluding that UVA1 should be considered as a therapeutic option in more darkly pigmented patients. Although more studies are needed to clarify this point, UVA1 is an option for all skin types. The long-term impact of UVA1 phototherapy and risk of carcinogenesis is not clear. Mouse model studies have demonstrated that UVA1 does induce reactive oxygen species and cyclobutane pyrimidine dimers that are known to induce mutations.11 However, no longitudinal studies exist examining the incidence of skin cancer in patients receiving UVA1. With this preliminary evidence in mind, it may be wise to use the same precautions as with UVA and UVB. Conclusion Phototherapy is a safe option for the treatment of many dermatologic conditions. Although phototherapy can cause side effects, such as photodamage and increased risk of skin cancer, through proper patient selection, it is possible to limit the impact of these side effects. Dr. Holly Kerr is a Senior Staff physician at Henry Ford Heath System, Detroit, MI, with a particular interest in phototherapy. She also specializes in contact dermatitis and transplant dermatology. Meredith Price is a fourth year medical student at Wayne State University in Detroit, MI. Disclosures: Dr. Kerr and Ms. Price have no conflict of interest with any of the material discussed in this article.
