Flagellate dermatitis refers to linear, erythematous lesions that resemble whip marks.
Differential diagnosis of flagellate dermatitis:
(1) whip marks (including self-flagellation)
(2) shiitake mushroom dermatitis (Lentinula edodes)
(3) excoriations
(4) cutaneous larva migrans
(5) contact allergy
(6) chemotherapy drugs (doxorubicin, bleomycin, bendamustine)
(7) Wood Ear (Auricularia auricula-judae, Judas ear, an edible fungus)
(8) jellyfish or Portuguese man o'war