Patient Presentation
A 12-year-old girl presented with asymptomatic bilateral hand hyperpigmentation that had been present for 10 days. The patient admitted to being an avid lover of lemons and occasionally drinking lemon juice. In addition, she stated that she spent much of her afternoons outdoors. The eruption was described by her parents as an erythematous pruritic plaque, which later turned light brown. She did not have any history of similar lesions, and her review of systems was unremarkable. She did not have any co-morbid conditions and was not taking any medications. Close contacts did not exhibit a similar condition. On physical examination, there were two well-defined hyperpigmented and mildly scaly patches on the dorsa of both hands. The patches began in the second and third interdigital clefts, and extended about 3 cm and 6 cm, respectively, in a linear pattern toward the wrist. The borders were slightly irregular but well differentiated from the adjacent skin. The pattern of hyperpigmentation was similar bilaterally. What Is Your Diagnosis? Turn to page 90 for an answer and for more details.
Diagnosis: Phytophotodermatitis
This case represents a phototoxic reaction that occurred due to the combined exposure of the patient to lemons, lemon juice and subsequent sunlight. Phytophotodermatitis (PPD) is an inflammatory eruption that occurs when the skin comes in contact with a photosensitizer and is subsequently exposed to radiation. The photosensitizer is the pigment furocoumarin, a lipid-soluble 8-methoxypsoralen.1 This pigment is found in various plants and vegetables, including celery,2-5 limes and lemons,6-10 figs,11,12 citrus fruits,13,14 parsley,15 sagebrush, goldenrod, chrysanthemum, ragweed and cocklebur.16 PPD is caused by the absorption of furocoumarin into keratinocytes and its irreversible binding to keratinocyte DNA after exposure to long-wavelength ultraviolet A (UV-A) radiation. The damage to DNA results in inhibition of DNA synthesis, inhibition of cell proliferation, and stimulation of melanin production.17 In order for PPD to develop, the pigment must be present in sufficient quantities, and the wavelength of the subsequent radiation must be within the photosensitizing compound’s action spectrum, typically in the UV-A 320-400 nanometer range.18 Phytophotodermatitis is commonly seen in workers with occupations that entail exposure to furocoumarin-containing products, such as agricultural workers, bartenders, florists and gardeners. It may also be seen in beachgoers, athletes and children. PPD has been listed as an occupational hazard among citrus workers and celery harvesters due to the high content of furocoumarins in these plants.19
Clinicopathological Features
Phytophotodermatitis is clinically evident as an acute reaction consisting of erythema, plaque formation, burning edema, hyperpigmentation and blistering and/or vesiculation within 24 hours, depending on the extent of exposure.18,19 Postinflammatory hyperpigmentation may follow but usually fades after 2 to 3 months. It may, however, become chronic if application of the offending substance continues. The shape and pattern of the lesions usually resemble the streaks from the juices containing the phototoxic compounds; hence, the hands and mouth are most commonly affected due to eating and handling of the offending plant. Suspicion of PPD should arise with characteristic presentation of bizarre and linear hyperpigmentation.20 Systemic manifestations are rare. However, one case of PPD was associated with hemolytic anemia and retinal hemorrhage.11 Histologic examination demonstrates single-cell epidermal necrosis. In more severe cases, confluent necrosis may lead to subepidermal and reticulate intra-epidermal vesiculation, followed by parakeratosis.21
Differential Diagnosis
Other conditions that mimic the clinical picture of PPD are fixed drug eruption, Berloque dermatitis, child abuse, type IV hypersensitivity reactions, erythema multiforme, chemical burns, herpes zoster, bullous impetigo, scalding, cellulitis and fungal infections.22 Fixed drug eruption tends to be annular, less bizarre in shape, and reappears chronically in the same location with repeated exposure to the offending agent. PPD, however, is acute in onset and appears in a “flow” pattern. Berloque dermatitis occurs when fragrance products containing bergamot oil are applied to the skin followed by exposure to sunlight.23 Bergapten is the photoactive component of bergamot oil, and exposure to sunlight after contact results in erythema and hyperpigmentation. For this reason, bergamot oil use is restricted in the United States, but is still used in “holy water” preparations and aromatherapeutic oils used by certain communities.24,25 Phytophotodermatitis may also present similarly to child abuse, and several cases of PPD incorrectly diagnosed as child abuse have been reported.26-30 To avoid misdiagnosis of PPD, elicit the patient’s history of contact with substances containing psoralens, perfume, or aromatherapy oils. Question patients in detail about exposure to sunlight or UV-A radiation. In the case of children, be sure to also question parents since contact exposure in small children can occur when parents have the offending substance on their hands. The chief histologic differential diagnosis is erythema multiforme, which shows parakeratosis and spongiosis.31 Conditions such as chemical burns, scalding, herpes zoster, bullous impetigo, cellulitis and fungal infections may also present in a similar manner. An inquiry into history of exposure to hot water and infection should clarify the diagnosis.
Managing Phytophotodermatitis
PPD is a clinical diagnosis based on history and physical examination. It is treated by withdrawal of the offending agent, with medication, and with time. In this particular case, cessation of the offending activities resulted in complete clearance of the eruption after a 60-day period. Topical corticosteroids, such as 0.1% triamcinolone cream (Aristocort A) may yield rapid improvement.22,31 They may improve clearing of erythema, but are not as helpful for hyperpigmentation. Hyperpigmentation takes more time to clear, and healing is heralded by desquamation of the necrotic epidermis.18 Cool compresses may be helpful during the acute phase with oral salicylates or other NSAIDs given for pain and blistering. Blistered areas should be kept clean to prevent secondary infection. In severe cases, antihistamines may be used for treatment of pruritis. Long-term treatment involves avoidance of psoralens or other photosensitizers, as future outbreaks are more likely if exposure continues. Preventative measures have been recommended, including education of grocery store employees, bartenders, gardeners and agricultural workers regarding PPD. Other recommendations include wearing gloves, using larger plastic produce bags and decreasing aesthetic celery leaf trimming.32 In addition, bartenders and grocery store workers should be advised to wash their hands before venturing outdoors.
Patient Presentation
A 12-year-old girl presented with asymptomatic bilateral hand hyperpigmentation that had been present for 10 days. The patient admitted to being an avid lover of lemons and occasionally drinking lemon juice. In addition, she stated that she spent much of her afternoons outdoors. The eruption was described by her parents as an erythematous pruritic plaque, which later turned light brown. She did not have any history of similar lesions, and her review of systems was unremarkable. She did not have any co-morbid conditions and was not taking any medications. Close contacts did not exhibit a similar condition. On physical examination, there were two well-defined hyperpigmented and mildly scaly patches on the dorsa of both hands. The patches began in the second and third interdigital clefts, and extended about 3 cm and 6 cm, respectively, in a linear pattern toward the wrist. The borders were slightly irregular but well differentiated from the adjacent skin. The pattern of hyperpigmentation was similar bilaterally. What Is Your Diagnosis? Turn to page 90 for an answer and for more details.
Diagnosis: Phytophotodermatitis
This case represents a phototoxic reaction that occurred due to the combined exposure of the patient to lemons, lemon juice and subsequent sunlight. Phytophotodermatitis (PPD) is an inflammatory eruption that occurs when the skin comes in contact with a photosensitizer and is subsequently exposed to radiation. The photosensitizer is the pigment furocoumarin, a lipid-soluble 8-methoxypsoralen.1 This pigment is found in various plants and vegetables, including celery,2-5 limes and lemons,6-10 figs,11,12 citrus fruits,13,14 parsley,15 sagebrush, goldenrod, chrysanthemum, ragweed and cocklebur.16 PPD is caused by the absorption of furocoumarin into keratinocytes and its irreversible binding to keratinocyte DNA after exposure to long-wavelength ultraviolet A (UV-A) radiation. The damage to DNA results in inhibition of DNA synthesis, inhibition of cell proliferation, and stimulation of melanin production.17 In order for PPD to develop, the pigment must be present in sufficient quantities, and the wavelength of the subsequent radiation must be within the photosensitizing compound’s action spectrum, typically in the UV-A 320-400 nanometer range.18 Phytophotodermatitis is commonly seen in workers with occupations that entail exposure to furocoumarin-containing products, such as agricultural workers, bartenders, florists and gardeners. It may also be seen in beachgoers, athletes and children. PPD has been listed as an occupational hazard among citrus workers and celery harvesters due to the high content of furocoumarins in these plants.19
Clinicopathological Features
Phytophotodermatitis is clinically evident as an acute reaction consisting of erythema, plaque formation, burning edema, hyperpigmentation and blistering and/or vesiculation within 24 hours, depending on the extent of exposure.18,19 Postinflammatory hyperpigmentation may follow but usually fades after 2 to 3 months. It may, however, become chronic if application of the offending substance continues. The shape and pattern of the lesions usually resemble the streaks from the juices containing the phototoxic compounds; hence, the hands and mouth are most commonly affected due to eating and handling of the offending plant. Suspicion of PPD should arise with characteristic presentation of bizarre and linear hyperpigmentation.20 Systemic manifestations are rare. However, one case of PPD was associated with hemolytic anemia and retinal hemorrhage.11 Histologic examination demonstrates single-cell epidermal necrosis. In more severe cases, confluent necrosis may lead to subepidermal and reticulate intra-epidermal vesiculation, followed by parakeratosis.21
Differential Diagnosis
Other conditions that mimic the clinical picture of PPD are fixed drug eruption, Berloque dermatitis, child abuse, type IV hypersensitivity reactions, erythema multiforme, chemical burns, herpes zoster, bullous impetigo, scalding, cellulitis and fungal infections.22 Fixed drug eruption tends to be annular, less bizarre in shape, and reappears chronically in the same location with repeated exposure to the offending agent. PPD, however, is acute in onset and appears in a “flow” pattern. Berloque dermatitis occurs when fragrance products containing bergamot oil are applied to the skin followed by exposure to sunlight.23 Bergapten is the photoactive component of bergamot oil, and exposure to sunlight after contact results in erythema and hyperpigmentation. For this reason, bergamot oil use is restricted in the United States, but is still used in “holy water” preparations and aromatherapeutic oils used by certain communities.24,25 Phytophotodermatitis may also present similarly to child abuse, and several cases of PPD incorrectly diagnosed as child abuse have been reported.26-30 To avoid misdiagnosis of PPD, elicit the patient’s history of contact with substances containing psoralens, perfume, or aromatherapy oils. Question patients in detail about exposure to sunlight or UV-A radiation. In the case of children, be sure to also question parents since contact exposure in small children can occur when parents have the offending substance on their hands. The chief histologic differential diagnosis is erythema multiforme, which shows parakeratosis and spongiosis.31 Conditions such as chemical burns, scalding, herpes zoster, bullous impetigo, cellulitis and fungal infections may also present in a similar manner. An inquiry into history of exposure to hot water and infection should clarify the diagnosis.
Managing Phytophotodermatitis
PPD is a clinical diagnosis based on history and physical examination. It is treated by withdrawal of the offending agent, with medication, and with time. In this particular case, cessation of the offending activities resulted in complete clearance of the eruption after a 60-day period. Topical corticosteroids, such as 0.1% triamcinolone cream (Aristocort A) may yield rapid improvement.22,31 They may improve clearing of erythema, but are not as helpful for hyperpigmentation. Hyperpigmentation takes more time to clear, and healing is heralded by desquamation of the necrotic epidermis.18 Cool compresses may be helpful during the acute phase with oral salicylates or other NSAIDs given for pain and blistering. Blistered areas should be kept clean to prevent secondary infection. In severe cases, antihistamines may be used for treatment of pruritis. Long-term treatment involves avoidance of psoralens or other photosensitizers, as future outbreaks are more likely if exposure continues. Preventative measures have been recommended, including education of grocery store employees, bartenders, gardeners and agricultural workers regarding PPD. Other recommendations include wearing gloves, using larger plastic produce bags and decreasing aesthetic celery leaf trimming.32 In addition, bartenders and grocery store workers should be advised to wash their hands before venturing outdoors.
Patient Presentation
A 12-year-old girl presented with asymptomatic bilateral hand hyperpigmentation that had been present for 10 days. The patient admitted to being an avid lover of lemons and occasionally drinking lemon juice. In addition, she stated that she spent much of her afternoons outdoors. The eruption was described by her parents as an erythematous pruritic plaque, which later turned light brown. She did not have any history of similar lesions, and her review of systems was unremarkable. She did not have any co-morbid conditions and was not taking any medications. Close contacts did not exhibit a similar condition. On physical examination, there were two well-defined hyperpigmented and mildly scaly patches on the dorsa of both hands. The patches began in the second and third interdigital clefts, and extended about 3 cm and 6 cm, respectively, in a linear pattern toward the wrist. The borders were slightly irregular but well differentiated from the adjacent skin. The pattern of hyperpigmentation was similar bilaterally. What Is Your Diagnosis? Turn to page 90 for an answer and for more details.
Diagnosis: Phytophotodermatitis
This case represents a phototoxic reaction that occurred due to the combined exposure of the patient to lemons, lemon juice and subsequent sunlight. Phytophotodermatitis (PPD) is an inflammatory eruption that occurs when the skin comes in contact with a photosensitizer and is subsequently exposed to radiation. The photosensitizer is the pigment furocoumarin, a lipid-soluble 8-methoxypsoralen.1 This pigment is found in various plants and vegetables, including celery,2-5 limes and lemons,6-10 figs,11,12 citrus fruits,13,14 parsley,15 sagebrush, goldenrod, chrysanthemum, ragweed and cocklebur.16 PPD is caused by the absorption of furocoumarin into keratinocytes and its irreversible binding to keratinocyte DNA after exposure to long-wavelength ultraviolet A (UV-A) radiation. The damage to DNA results in inhibition of DNA synthesis, inhibition of cell proliferation, and stimulation of melanin production.17 In order for PPD to develop, the pigment must be present in sufficient quantities, and the wavelength of the subsequent radiation must be within the photosensitizing compound’s action spectrum, typically in the UV-A 320-400 nanometer range.18 Phytophotodermatitis is commonly seen in workers with occupations that entail exposure to furocoumarin-containing products, such as agricultural workers, bartenders, florists and gardeners. It may also be seen in beachgoers, athletes and children. PPD has been listed as an occupational hazard among citrus workers and celery harvesters due to the high content of furocoumarins in these plants.19
Clinicopathological Features
Phytophotodermatitis is clinically evident as an acute reaction consisting of erythema, plaque formation, burning edema, hyperpigmentation and blistering and/or vesiculation within 24 hours, depending on the extent of exposure.18,19 Postinflammatory hyperpigmentation may follow but usually fades after 2 to 3 months. It may, however, become chronic if application of the offending substance continues. The shape and pattern of the lesions usually resemble the streaks from the juices containing the phototoxic compounds; hence, the hands and mouth are most commonly affected due to eating and handling of the offending plant. Suspicion of PPD should arise with characteristic presentation of bizarre and linear hyperpigmentation.20 Systemic manifestations are rare. However, one case of PPD was associated with hemolytic anemia and retinal hemorrhage.11 Histologic examination demonstrates single-cell epidermal necrosis. In more severe cases, confluent necrosis may lead to subepidermal and reticulate intra-epidermal vesiculation, followed by parakeratosis.21
Differential Diagnosis
Other conditions that mimic the clinical picture of PPD are fixed drug eruption, Berloque dermatitis, child abuse, type IV hypersensitivity reactions, erythema multiforme, chemical burns, herpes zoster, bullous impetigo, scalding, cellulitis and fungal infections.22 Fixed drug eruption tends to be annular, less bizarre in shape, and reappears chronically in the same location with repeated exposure to the offending agent. PPD, however, is acute in onset and appears in a “flow” pattern. Berloque dermatitis occurs when fragrance products containing bergamot oil are applied to the skin followed by exposure to sunlight.23 Bergapten is the photoactive component of bergamot oil, and exposure to sunlight after contact results in erythema and hyperpigmentation. For this reason, bergamot oil use is restricted in the United States, but is still used in “holy water” preparations and aromatherapeutic oils used by certain communities.24,25 Phytophotodermatitis may also present similarly to child abuse, and several cases of PPD incorrectly diagnosed as child abuse have been reported.26-30 To avoid misdiagnosis of PPD, elicit the patient’s history of contact with substances containing psoralens, perfume, or aromatherapy oils. Question patients in detail about exposure to sunlight or UV-A radiation. In the case of children, be sure to also question parents since contact exposure in small children can occur when parents have the offending substance on their hands. The chief histologic differential diagnosis is erythema multiforme, which shows parakeratosis and spongiosis.31 Conditions such as chemical burns, scalding, herpes zoster, bullous impetigo, cellulitis and fungal infections may also present in a similar manner. An inquiry into history of exposure to hot water and infection should clarify the diagnosis.
Managing Phytophotodermatitis
PPD is a clinical diagnosis based on history and physical examination. It is treated by withdrawal of the offending agent, with medication, and with time. In this particular case, cessation of the offending activities resulted in complete clearance of the eruption after a 60-day period. Topical corticosteroids, such as 0.1% triamcinolone cream (Aristocort A) may yield rapid improvement.22,31 They may improve clearing of erythema, but are not as helpful for hyperpigmentation. Hyperpigmentation takes more time to clear, and healing is heralded by desquamation of the necrotic epidermis.18 Cool compresses may be helpful during the acute phase with oral salicylates or other NSAIDs given for pain and blistering. Blistered areas should be kept clean to prevent secondary infection. In severe cases, antihistamines may be used for treatment of pruritis. Long-term treatment involves avoidance of psoralens or other photosensitizers, as future outbreaks are more likely if exposure continues. Preventative measures have been recommended, including education of grocery store employees, bartenders, gardeners and agricultural workers regarding PPD. Other recommendations include wearing gloves, using larger plastic produce bags and decreasing aesthetic celery leaf trimming.32 In addition, bartenders and grocery store workers should be advised to wash their hands before venturing outdoors.
