Poison ivy - oak - sumac dermatitis in Adult
See also in: External and Internal EyeAlerts and Notices
Synopsis

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 ethnicities and ages, although elderly individuals 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.
Codes
ICD10CM:L23.7 – Allergic contact dermatitis due to plants, except food
SNOMEDCT:
200823002 – Allergic dermatitis due to poison ivy
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
- 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
- Stasis dermatitis
- Nummular dermatitis
- Bullous impetigo
- Cellulitis or erysipelas
- Bullous tinea pedis
- Herpes simplex infection
- Zoster
- Arthropod bites or stings
- Scabies can also have linear lesions, vesiculation, and be extremely pruritic.
- Autoimmune blistering diseases, including the pemphigus group, bullous pemphigoid, linear IgA dermatosis, dermatitis herpetiformis, and epidermolysis bullosa acquisita, among others
- Porphyria cutanea tarda
- Solar urticaria
- Drug-induced phototoxic reaction
- Phytophotodermatitis from exposure to limes or other psoralen-containing plants
- Melanocytic lesions including melanoma
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Reviewed:03/05/2017
Last Updated:11/10/2022
Last Updated:11/10/2022
Poison ivy - oak - sumac dermatitis in Adult
See also in: External and Internal Eye