Poison ivy - oak - sumac dermatitis in Child
Black dot (or black spot) poison ivy is the presence of black residue on the skin surface that occurs when a high concentration of urushiol contacts the skin and undergoes oxidization in the presence of moisture.
Poison ivy, oak, or sumac dermatitis can occur in people of all races and ages, although the elderly and very young children may be less susceptible. Pruritus is often severe. Scratching does not spread the eruption: vesicles and plaques first appear at sites of contact with high concentrations of antigen and then, as the immune response increases, skin that has contacted lower antigen concentrations becomes involved. The contact dermatitis will persist for 3-4 weeks if not treated.
L23.7 – Allergic contact dermatitis due to plants, except food
200823002 – Allergic dermatitis due to poison ivy
- Consider other causes of allergic contact dermatitis, including other plants. Mangos contain an antigen that cross-reacts with poison ivy oil and may result in perioral contact dermatitis.
- Hogweed dermatitis
- Atopic dermatitis
- Nummular dermatitis
- Bullous impetigo
- Cellulitis or erysipelas
- Herpes simplex virus (HSV) infection – Lesions often coalesce on a red base, usually periorificial; there is often a prodrome of pain and burning. HSV may be associated with fever, malaise, and tender lymphadenopathy. Viral polymerase chain reaction (PCR) and direct fluorescent antibody (DFA) will reveal the virus.
- Herpes zoster – Localized to dermatomes, grouped vesicles and bullae on a red base with a history of varicella. Viral PCR and DFA will reveal the virus.
- Arthropod bites or stings
- Scabies can also have vesicles and be extremely pruritic, but it is usually symmetric and involves areas protected by clothing.
- Phytophotodermatitis from exposure to limes or other psoralen-containing plants
- Melanocytic lesions, including melanoma