Antibodies to piloerector muscle in a patient with lupus-lichen planus overlap syndrome

CONTEXT Smoot muscle (SM) is a muscle tissue that contracts without conscious control, made up of spindle-shaped, untreated cells with single nuclei and found in the walls of the internal organs, such us the stomach, intestine, bladder, and blood vessels, excluding the heart and in the (arrector pili) muscle in the skin. CASE REPORT A 59 Caucasian woman was evaluated for pruritic rash and violaceous plaques mostly in the upper extremities with some with ulcers in her mouth. Biopsies for hematoxylin and eosin and immunohistochemistry examination, as well as for direct immunofluorescence analysis were performed. The hematoxylin and eosin staining demonstrated mild epidermal atrophy with focal follicular plugging. A mild interface infiltrate of lymphocytes and histiocytes and a superficial and deep, perivascular and periadnexal dermal infiltrate of lymphocytes, histiocytes and plasma cells was observed. Was difficult to diagnose as either lichen planus or lupus erythematosus. The histological studies from two places showed features of both lupus erythematosus and lichen planus. The direct immunofluorescence revealed focal deposits of immunoglobulins IgG, present at the basement membrane junction of the skin as well as in the sweat glands of IgM, fibrinogen and complement/C3. In addition, deposits of IgE surrounding the superficial dermal blood vessels and ecrine glands. Antibodies to piloerector muscle using several immunoglobulins, corroborated by immunohistochemistry stains. CONCLUSIONS This is the first case reporting autoantibodies to the piloerector muscle in a patient having mixed clinical and histopathological diagnoses of lupus/lichen planus overlapping syndrome with strong IgE immune response.