Hypertrophic lichen planus-like atopic dermatitis: a case report

Results The lesions started at age 18 during the patient ́s first pregnancy and had a predominant flexural distribution pattern. At the physical exam, the patient presented with erythema and infiltrative lesions in forearm and periorbital regions, and scaly erythematous papules, especially in inferior extremities. Some of these lesions presented an ulcerous center and had linear form. The patient had high specific serum IgE levels for house dust mites (Dermatophagoides farinae and D. pteronyssinus), grass and dog; sea food, fish, soy, wheat and latex. Serum total IgE was 11,100kU/L, and serology for hepatitis B and C was negative. The patient was treated with antihistamines, topical emollients and oral corticosteroids with low improvement. Because of this atypical presentation, other differential diagnoses were considered, including hypertrophic lichen planus. Skin biopsy was performed, showing hyperkeratosis, sub-acute spongiotic dermatitis and moderate acanthosis, compatible with atopic dermatitis and an evolution to lichen simplex chronicus. Conclusions Hypertrophic lichen planus is one of the differential diagnosis of atopic dermatitis and it commonly involves the flexor surfaces of the extremities bilaterally. Adultonset AD can present with non-typical morphology and localization, therefore it is important to distinguish these two entities, since lichen planus can be associated with other diseases, such as viral hepatitis.