Poison ivy, oak, sumac dermatitis in Child
These species show regional variations in the nature of the plant including growth pattern, leaf characteristics, and flowering.
After exposure, the rash begins to appear within 1-2 days in previously sensitized individuals; in the newly sensitized, it may be delayed 2-3 weeks. As the resin is very stable, occult contact may occur from contaminated clothing, gear, or vegetation, even after months have elapsed.
L23.7 – Allergic contact dermatitis due to plants, except food
200823002 – Allergic dermatitis due to poison ivy
Differential Diagnosis & Pitfalls
- Phytophotodermatitis – Similar presentation but due to plant material and ultraviolet (UV) exposure. Hogweed, citrus fruits, celery, wild parsnip, wild carrots, and oil of bergamot are among the more common causes.
- Dermatitis due to other Anacardiaceae genera – mango, cashew, pistachio
- Allergic contact dermatitis to some other antigen
- Arthropod bite or sting reaction – Exaggerated vesiculobullous reactions may be associated with chronic lymphocytic leukemia, other hematological malignancies, and HIV.
- Bullous impetigo – more scattered, fragile bullae; golden crusts
- Scabies – rarely vesicular
- Herpes zoster – Inquire regarding prodrome of pain or burning. Viral polymerase chain reaction (PCR) and/or direct fluorescent antibody (DFA) can be used to confirm.
- Zosteriform herpes simplex – Inquire regarding sensory prodrome and possible previous episode. Viral PCR and/or DFA can be used to confirm.
- Erythropoietic protoporphyria
- Cellulitis or erysipelas
- Solar urticaria
- Bullous tinea pedis – usually feet and possibly ankles, may additionally involve one hand
- Autoimmune blistering diseases
- Atopic dermatitis
- Nummular dermatitis
- Melanocytic lesions, including melanoma