A case of localized scleroderma, psoriasis and signs of dermatomyositis combination: diagnostic and therapeutic aspects

We present an observation of three autoimmune dermatoses combination: scleroderma, psoriasis and signs of dermatomyositis in a 46-year-old man. The clinical case is of interest in relation to diagnosis, search for common pathogenetic mechanisms and choice of optimal therapy. In May 2023, the patient developed scleroderma plaques on the abdomen, in July of the same year — facial erythema (diagnosed as rosacea), in November — psoriatic rashes on the extremities and Gottron papules on the hands. Histological examination of biopsy samples from different foci, which revealed signs of localized scleroderma (thickened collagen, mucinosis), psoriasis (parakeratosis, Munro’s microabscesses) and dermatomyositis (changes typical for Gottron papules), was performed. Laboratory parameters without pathological findings. Combination therapy was prescribed: methotrexate 25 mg/week subcutaneously and hydroxychloroquine 200 mg twice daily. A 3-month follow-up showed a decrease in infiltration and erythema. The case demonstrates the importance of multifocal biopsy in overlap syndromes as well as the possibility of two or more immune-related diseases combination. The presence of three dermatoses, each of which has its own pathogenetic development pathway and affects the other two, determines the severity of the clinical picture.