The most common plant rashes may be classified as allergic or chemical irritant dermatitis. The dermatitis caused by poison ivy, poison oak and poison sumac — the “classic” allergic contact dermatitis — involves a delayed type IV hypersensitivity reaction. Consequently, the allergic contact dermatitis caused by poison ivy requires prior sensitization and occurs many hours after exposure to the plant. Chemical irritant contact dermatitis from plants generally occurs in all individuals exposed to adequate amounts of the chemical. The threshold for irritation is lowered when the skin barrier is damaged, such as with florists whose hands are constantly wet.
Test your knowledge of these common rashes.
Case 1
Diagnosis:_______________________________________________________________________________________________________________________________________________________________________________________
1. This same clinical presentation, with the “hallmark” linear vesicles may also be seen in patients exposed to poison oak or poison sumac.
True False
2. This is not a true allergy.
True False
3. Poison ivy, poison oak and poison sumac are members of the Anacardiaceae family and Toxicodendron genus.
True False
4. Members of the family Anacardiaceae do not cause more allergic
contact dermatitis than all other plant families combined.
True False
5. If the treatment requires systemic steroids, the length of therapy should be 7 days or less.
True False
Case 2
Diagnosis:___________________________________________________________
____________________________________________________________________
1. Poison ivy, or rhus dermatitis, may be prevented if the exposed skin is washed within 15 minutes of exposure.
True False
2. Urushiol, the small molecule that is the allergen in poison ivy,
is not water-soluble.
True False
3. Urushiol does not link to receptors on the surface of Langerhans cells found in the epidermis.
True False
4. These Langerhans cells do not migrate to local lymph nodes and recruit “memory” lymphocytes (CD4+ T-helper cells) that circulate.
True False
5. When the “memory” lymphocytes subsequently meet urushiol in the skin, they create inflammation by releasing cytokines including interleukins 4,6, 8, and others, as well as TNF-alpha and intercellular adhesion molecule-1 (ICAM-1).
True False
Case 3
Diagnosis:_________________________________________________________________________________________________________________________________________________________________________________
1. Irritant contact dermatitis from plants is most often seen in florists.
True False
2. The chemical causing “daffodil itch” (irritant contact dermatitis) is calcium oxalate.
True False
3. This patient, with “daffodil itch”, would have a positive patch
test to calcium oxalate.
True False
4. Persistently wet hands or a prior history of dyshidrotic eczema do not predispose a patient for irritant contact dermatitis.
True False
5. In the rare situation of allergic contact dermatitis from daffodils, the allergen is tulipalin A.
True False
Case 4
Diagnosis:______________________________________________________________________________________________________________________________________________________________________________
1. Urushiol self-melanizes on exposure to oxygen and gives poison ivy the name “black dot dermatitis.”
True False
2. Similar black dots found on the skin are not seen on the leaves of the plant.
True False
3. Poison ivy can spread from the blister fluid.
True False
4. Patients with a history of poison ivy react when exposed to cashew nut shell oil, mango fruit skin, crushed berries from the Brazilian pepper tree, or sap from the Japanese lacquer tree.
True False
5. Exposure to wood smoke from logs covered with poison ivy vines will not cause a severe airborne type of poison ivy in a susceptible person.
True False
Case 5
Diagnosis:_________________________________________________________________________________________________________________
_____________________________________________________________
1. Poison ivy may affect up to 50% of the American population, while “daffodil itch” may affect up to 50% of florists.
True False
2. Breaking the node on the stem of an Impatiens capensis (spotted jewelweed) plant and applying the liquid to a lesion of poison ivy is not a “folklore” treatment for poison ivy.
True False
3. A severe worsening of poison ivy dermatitis cannot develop from a second contact dermatitis arising from treatment with topical diphenhydramine.
True False
4. Marked scrotal edema is a feature of severe poison ivy.
True False
5. A 70-year-old man, with a past history of poison ivy 50 years ago, can still get poison ivy today.
True False
Treating Contact Dermatitis from Plants and Flowers
The main goals for treating contact dermatitis are to clear the rash and relieve pruritus. Treatment options can vary depending on the severity of the reaction. Severity can be measured based upon the lesion type, the body surface area affected and the impact on the patient’s quality of life.
The first step in treatment of all contact dermatitis is to remove the cause of the rash — without doing this, the rash will not resolve. Washing with soap and water, or just water, will remove the poison ivy allergen and other contactants. For irritant contactants, barrier creams, such as Nouriva Repair or Ivy Block, can be a helpful addition to repair the damaged skin barrier. Depending on the severity of the rash, various prescription treatment options are present.
Mild – Mid-potency topical corticosteroids, such as hydrocortisone butyrate 0.1% (Locoid Lipocream) or fluticasone propionate (Cutivate), can be utilized to effectively treat the inflammation. A topical anesthetic can be applied to help reduce the pruritus. A non-steroidal anti-inflammatory, such as tacrolimus (Protopic) might be used if there’s involvement in an area where corticosteroids should be avoided. A combination product of a low-potency topical corticosteroid and an anesthetic, such as pramoxine hydrochloride
(Enzone, Pramosone), might be the ideal therapy for pediatric patients.
Moderate – Mid- to high-potency topical steroids, such as Locoid Lipocream, mometasone furoate (Elocon), or fluocinonide (Lidex, Vanos) can be used to relieve the inflammation. An oral antihistamine can be supplied to help reduce the pruritus and, depending on the selection, help pediatric patients relax at bedtime.
Severe – Oral or intramuscular corticosteroids can be provided for rapid relief. Topical application, except for cold-water compresses, is difficult for patients because of the large amount of irritated body surface area. Ultra-high-potency
corticosteroids such as clobetasol propionate (Clobetasol, Clobex, Olux and Temovate) can be used as well.
Suggested READING
Fisher AA: Poison ivy/oak/sumac. Part II: Specific features. Cutis 1996 Jul; 58(1): 22-4.
Fisher AA: Poison ivy/oak dermatitis. Part I: Prevention —soap and water, topical barriers, hyposensitization. Cutis 1996 Jun; 57(6): 384-6.
Kurlan JG, Lucky AW: Black spot poison ivy: A report of 5 cases and a review of the literature. J Am Acad Dermatol 2001 Aug; 45(2): 246-9.
Crawford GH, McGovern TW: Botanical Dermatology.
emedicine.com/derm/topic904.htm.
Hogan D: Allergic contact dermatitis. emedicine.com/derm/topic84.htm.
Long D, Ballentine NH, Marks JG Jr: Treatment of poison ivy/oak allergic contact dermatitis with an extract of
jewelweed. Am J Contact Dermat 1997 Sep; 8(3): 150-3.
Guin JD, Gillis WT, Beaman JH: Recognizing the Toxicodendrons (poison ivy, poison oak, and poison sumac).
J Am Acad Dermatol 1981 Jan; 4(1): 99-114.
Guin JD: The black spot test for recognizing poison ivy and related species. J Am Acad Dermatol 1980 Apr; 2(4): 332-3.
Answer KEY
Case #1: Poison ivy, allergic contact dermatitis, rhus dermatitis
1. T 2. F 3. T 4. F 5. F (The length of therapy for systemic steroids should be slowly tapered over 2 to 3 weeks to prevent a “recurrence” of the dermatitis)
Case #2: Poison ivy
1. T 2. F 3. F 4. F 5. T
Case #3: Irritant contact dermatitis
1. T 2. T 3. F 4. F 5. T
Case #4: Poison ivy, “black dot” dermatitis
1. T 2. F 3. F 4. T 5. F
Case #5: Poison ivy
1. T 2. F 3. F 4. T 5. T
The most common plant rashes may be classified as allergic or chemical irritant dermatitis. The dermatitis caused by poison ivy, poison oak and poison sumac — the “classic” allergic contact dermatitis — involves a delayed type IV hypersensitivity reaction. Consequently, the allergic contact dermatitis caused by poison ivy requires prior sensitization and occurs many hours after exposure to the plant. Chemical irritant contact dermatitis from plants generally occurs in all individuals exposed to adequate amounts of the chemical. The threshold for irritation is lowered when the skin barrier is damaged, such as with florists whose hands are constantly wet.
Test your knowledge of these common rashes.
Case 1
Diagnosis:_______________________________________________________________________________________________________________________________________________________________________________________
1. This same clinical presentation, with the “hallmark” linear vesicles may also be seen in patients exposed to poison oak or poison sumac.
True False
2. This is not a true allergy.
True False
3. Poison ivy, poison oak and poison sumac are members of the Anacardiaceae family and Toxicodendron genus.
True False
4. Members of the family Anacardiaceae do not cause more allergic
contact dermatitis than all other plant families combined.
True False
5. If the treatment requires systemic steroids, the length of therapy should be 7 days or less.
True False
Case 2
Diagnosis:___________________________________________________________
____________________________________________________________________
1. Poison ivy, or rhus dermatitis, may be prevented if the exposed skin is washed within 15 minutes of exposure.
True False
2. Urushiol, the small molecule that is the allergen in poison ivy,
is not water-soluble.
True False
3. Urushiol does not link to receptors on the surface of Langerhans cells found in the epidermis.
True False
4. These Langerhans cells do not migrate to local lymph nodes and recruit “memory” lymphocytes (CD4+ T-helper cells) that circulate.
True False
5. When the “memory” lymphocytes subsequently meet urushiol in the skin, they create inflammation by releasing cytokines including interleukins 4,6, 8, and others, as well as TNF-alpha and intercellular adhesion molecule-1 (ICAM-1).
True False
Case 3
Diagnosis:_________________________________________________________________________________________________________________________________________________________________________________
1. Irritant contact dermatitis from plants is most often seen in florists.
True False
2. The chemical causing “daffodil itch” (irritant contact dermatitis) is calcium oxalate.
True False
3. This patient, with “daffodil itch”, would have a positive patch
test to calcium oxalate.
True False
4. Persistently wet hands or a prior history of dyshidrotic eczema do not predispose a patient for irritant contact dermatitis.
True False
5. In the rare situation of allergic contact dermatitis from daffodils, the allergen is tulipalin A.
True False
Case 4
Diagnosis:______________________________________________________________________________________________________________________________________________________________________________
1. Urushiol self-melanizes on exposure to oxygen and gives poison ivy the name “black dot dermatitis.”
True False
2. Similar black dots found on the skin are not seen on the leaves of the plant.
True False
3. Poison ivy can spread from the blister fluid.
True False
4. Patients with a history of poison ivy react when exposed to cashew nut shell oil, mango fruit skin, crushed berries from the Brazilian pepper tree, or sap from the Japanese lacquer tree.
True False
5. Exposure to wood smoke from logs covered with poison ivy vines will not cause a severe airborne type of poison ivy in a susceptible person.
True False
Case 5
Diagnosis:_________________________________________________________________________________________________________________
_____________________________________________________________
1. Poison ivy may affect up to 50% of the American population, while “daffodil itch” may affect up to 50% of florists.
True False
2. Breaking the node on the stem of an Impatiens capensis (spotted jewelweed) plant and applying the liquid to a lesion of poison ivy is not a “folklore” treatment for poison ivy.
True False
3. A severe worsening of poison ivy dermatitis cannot develop from a second contact dermatitis arising from treatment with topical diphenhydramine.
True False
4. Marked scrotal edema is a feature of severe poison ivy.
True False
5. A 70-year-old man, with a past history of poison ivy 50 years ago, can still get poison ivy today.
True False
Treating Contact Dermatitis from Plants and Flowers
The main goals for treating contact dermatitis are to clear the rash and relieve pruritus. Treatment options can vary depending on the severity of the reaction. Severity can be measured based upon the lesion type, the body surface area affected and the impact on the patient’s quality of life.
The first step in treatment of all contact dermatitis is to remove the cause of the rash — without doing this, the rash will not resolve. Washing with soap and water, or just water, will remove the poison ivy allergen and other contactants. For irritant contactants, barrier creams, such as Nouriva Repair or Ivy Block, can be a helpful addition to repair the damaged skin barrier. Depending on the severity of the rash, various prescription treatment options are present.
Mild – Mid-potency topical corticosteroids, such as hydrocortisone butyrate 0.1% (Locoid Lipocream) or fluticasone propionate (Cutivate), can be utilized to effectively treat the inflammation. A topical anesthetic can be applied to help reduce the pruritus. A non-steroidal anti-inflammatory, such as tacrolimus (Protopic) might be used if there’s involvement in an area where corticosteroids should be avoided. A combination product of a low-potency topical corticosteroid and an anesthetic, such as pramoxine hydrochloride
(Enzone, Pramosone), might be the ideal therapy for pediatric patients.
Moderate – Mid- to high-potency topical steroids, such as Locoid Lipocream, mometasone furoate (Elocon), or fluocinonide (Lidex, Vanos) can be used to relieve the inflammation. An oral antihistamine can be supplied to help reduce the pruritus and, depending on the selection, help pediatric patients relax at bedtime.
Severe – Oral or intramuscular corticosteroids can be provided for rapid relief. Topical application, except for cold-water compresses, is difficult for patients because of the large amount of irritated body surface area. Ultra-high-potency
corticosteroids such as clobetasol propionate (Clobetasol, Clobex, Olux and Temovate) can be used as well.
Suggested READING
Fisher AA: Poison ivy/oak/sumac. Part II: Specific features. Cutis 1996 Jul; 58(1): 22-4.
Fisher AA: Poison ivy/oak dermatitis. Part I: Prevention —soap and water, topical barriers, hyposensitization. Cutis 1996 Jun; 57(6): 384-6.
Kurlan JG, Lucky AW: Black spot poison ivy: A report of 5 cases and a review of the literature. J Am Acad Dermatol 2001 Aug; 45(2): 246-9.
Crawford GH, McGovern TW: Botanical Dermatology.
emedicine.com/derm/topic904.htm.
Hogan D: Allergic contact dermatitis. emedicine.com/derm/topic84.htm.
Long D, Ballentine NH, Marks JG Jr: Treatment of poison ivy/oak allergic contact dermatitis with an extract of
jewelweed. Am J Contact Dermat 1997 Sep; 8(3): 150-3.
Guin JD, Gillis WT, Beaman JH: Recognizing the Toxicodendrons (poison ivy, poison oak, and poison sumac).
J Am Acad Dermatol 1981 Jan; 4(1): 99-114.
Guin JD: The black spot test for recognizing poison ivy and related species. J Am Acad Dermatol 1980 Apr; 2(4): 332-3.
Answer KEY
Case #1: Poison ivy, allergic contact dermatitis, rhus dermatitis
1. T 2. F 3. T 4. F 5. F (The length of therapy for systemic steroids should be slowly tapered over 2 to 3 weeks to prevent a “recurrence” of the dermatitis)
Case #2: Poison ivy
1. T 2. F 3. F 4. F 5. T
Case #3: Irritant contact dermatitis
1. T 2. T 3. F 4. F 5. T
Case #4: Poison ivy, “black dot” dermatitis
1. T 2. F 3. F 4. T 5. F
Case #5: Poison ivy
1. T 2. F 3. F 4. T 5. T
The most common plant rashes may be classified as allergic or chemical irritant dermatitis. The dermatitis caused by poison ivy, poison oak and poison sumac — the “classic” allergic contact dermatitis — involves a delayed type IV hypersensitivity reaction. Consequently, the allergic contact dermatitis caused by poison ivy requires prior sensitization and occurs many hours after exposure to the plant. Chemical irritant contact dermatitis from plants generally occurs in all individuals exposed to adequate amounts of the chemical. The threshold for irritation is lowered when the skin barrier is damaged, such as with florists whose hands are constantly wet.
Test your knowledge of these common rashes.
Case 1
Diagnosis:_______________________________________________________________________________________________________________________________________________________________________________________
1. This same clinical presentation, with the “hallmark” linear vesicles may also be seen in patients exposed to poison oak or poison sumac.
True False
2. This is not a true allergy.
True False
3. Poison ivy, poison oak and poison sumac are members of the Anacardiaceae family and Toxicodendron genus.
True False
4. Members of the family Anacardiaceae do not cause more allergic
contact dermatitis than all other plant families combined.
True False
5. If the treatment requires systemic steroids, the length of therapy should be 7 days or less.
True False
Case 2
Diagnosis:___________________________________________________________
____________________________________________________________________
1. Poison ivy, or rhus dermatitis, may be prevented if the exposed skin is washed within 15 minutes of exposure.
True False
2. Urushiol, the small molecule that is the allergen in poison ivy,
is not water-soluble.
True False
3. Urushiol does not link to receptors on the surface of Langerhans cells found in the epidermis.
True False
4. These Langerhans cells do not migrate to local lymph nodes and recruit “memory” lymphocytes (CD4+ T-helper cells) that circulate.
True False
5. When the “memory” lymphocytes subsequently meet urushiol in the skin, they create inflammation by releasing cytokines including interleukins 4,6, 8, and others, as well as TNF-alpha and intercellular adhesion molecule-1 (ICAM-1).
True False
Case 3
Diagnosis:_________________________________________________________________________________________________________________________________________________________________________________
1. Irritant contact dermatitis from plants is most often seen in florists.
True False
2. The chemical causing “daffodil itch” (irritant contact dermatitis) is calcium oxalate.
True False
3. This patient, with “daffodil itch”, would have a positive patch
test to calcium oxalate.
True False
4. Persistently wet hands or a prior history of dyshidrotic eczema do not predispose a patient for irritant contact dermatitis.
True False
5. In the rare situation of allergic contact dermatitis from daffodils, the allergen is tulipalin A.
True False
Case 4
Diagnosis:______________________________________________________________________________________________________________________________________________________________________________
1. Urushiol self-melanizes on exposure to oxygen and gives poison ivy the name “black dot dermatitis.”
True False
2. Similar black dots found on the skin are not seen on the leaves of the plant.
True False
3. Poison ivy can spread from the blister fluid.
True False
4. Patients with a history of poison ivy react when exposed to cashew nut shell oil, mango fruit skin, crushed berries from the Brazilian pepper tree, or sap from the Japanese lacquer tree.
True False
5. Exposure to wood smoke from logs covered with poison ivy vines will not cause a severe airborne type of poison ivy in a susceptible person.
True False
Case 5
Diagnosis:_________________________________________________________________________________________________________________
_____________________________________________________________
1. Poison ivy may affect up to 50% of the American population, while “daffodil itch” may affect up to 50% of florists.
True False
2. Breaking the node on the stem of an Impatiens capensis (spotted jewelweed) plant and applying the liquid to a lesion of poison ivy is not a “folklore” treatment for poison ivy.
True False
3. A severe worsening of poison ivy dermatitis cannot develop from a second contact dermatitis arising from treatment with topical diphenhydramine.
True False
4. Marked scrotal edema is a feature of severe poison ivy.
True False
5. A 70-year-old man, with a past history of poison ivy 50 years ago, can still get poison ivy today.
True False
Treating Contact Dermatitis from Plants and Flowers
The main goals for treating contact dermatitis are to clear the rash and relieve pruritus. Treatment options can vary depending on the severity of the reaction. Severity can be measured based upon the lesion type, the body surface area affected and the impact on the patient’s quality of life.
The first step in treatment of all contact dermatitis is to remove the cause of the rash — without doing this, the rash will not resolve. Washing with soap and water, or just water, will remove the poison ivy allergen and other contactants. For irritant contactants, barrier creams, such as Nouriva Repair or Ivy Block, can be a helpful addition to repair the damaged skin barrier. Depending on the severity of the rash, various prescription treatment options are present.
Mild – Mid-potency topical corticosteroids, such as hydrocortisone butyrate 0.1% (Locoid Lipocream) or fluticasone propionate (Cutivate), can be utilized to effectively treat the inflammation. A topical anesthetic can be applied to help reduce the pruritus. A non-steroidal anti-inflammatory, such as tacrolimus (Protopic) might be used if there’s involvement in an area where corticosteroids should be avoided. A combination product of a low-potency topical corticosteroid and an anesthetic, such as pramoxine hydrochloride
(Enzone, Pramosone), might be the ideal therapy for pediatric patients.
Moderate – Mid- to high-potency topical steroids, such as Locoid Lipocream, mometasone furoate (Elocon), or fluocinonide (Lidex, Vanos) can be used to relieve the inflammation. An oral antihistamine can be supplied to help reduce the pruritus and, depending on the selection, help pediatric patients relax at bedtime.
Severe – Oral or intramuscular corticosteroids can be provided for rapid relief. Topical application, except for cold-water compresses, is difficult for patients because of the large amount of irritated body surface area. Ultra-high-potency
corticosteroids such as clobetasol propionate (Clobetasol, Clobex, Olux and Temovate) can be used as well.
Suggested READING
Fisher AA: Poison ivy/oak/sumac. Part II: Specific features. Cutis 1996 Jul; 58(1): 22-4.
Fisher AA: Poison ivy/oak dermatitis. Part I: Prevention —soap and water, topical barriers, hyposensitization. Cutis 1996 Jun; 57(6): 384-6.
Kurlan JG, Lucky AW: Black spot poison ivy: A report of 5 cases and a review of the literature. J Am Acad Dermatol 2001 Aug; 45(2): 246-9.
Crawford GH, McGovern TW: Botanical Dermatology.
emedicine.com/derm/topic904.htm.
Hogan D: Allergic contact dermatitis. emedicine.com/derm/topic84.htm.
Long D, Ballentine NH, Marks JG Jr: Treatment of poison ivy/oak allergic contact dermatitis with an extract of
jewelweed. Am J Contact Dermat 1997 Sep; 8(3): 150-3.
Guin JD, Gillis WT, Beaman JH: Recognizing the Toxicodendrons (poison ivy, poison oak, and poison sumac).
J Am Acad Dermatol 1981 Jan; 4(1): 99-114.
Guin JD: The black spot test for recognizing poison ivy and related species. J Am Acad Dermatol 1980 Apr; 2(4): 332-3.
Answer KEY
Case #1: Poison ivy, allergic contact dermatitis, rhus dermatitis
1. T 2. F 3. T 4. F 5. F (The length of therapy for systemic steroids should be slowly tapered over 2 to 3 weeks to prevent a “recurrence” of the dermatitis)
Case #2: Poison ivy
1. T 2. F 3. F 4. F 5. T
Case #3: Irritant contact dermatitis
1. T 2. T 3. F 4. F 5. T
Case #4: Poison ivy, “black dot” dermatitis
1. T 2. F 3. F 4. T 5. F
Case #5: Poison ivy
1. T 2. F 3. F 4. T 5. T
