Annular plaque-type psoriasis

A 23-year-old man presented with a 5-year history of a slowly progressive annular rash. Initially, the lesions appeared as isolated plaques; however, over time, they gradually enlarged, and additional lesions developed. The patient denied pain or systemic symptoms and reported a negative family history of dermatologic diseases. He also denied taking any medications and had no relevant environmental or occupational exposures. Physical examination revealed multiple erythematous, firm, annular plaques with well-defined borders and fine peripheral scaling. The lesions were symmetrically distributed, predominantly involving the trunk and upper limbs (Fig. 1). No mucosal involvement was observed. Examination of the nails showed no abnormalities, including pitting, onycholysis, or subungual hyperkeratosis. Auspitz's sign was positive, demonstrated by pinpoint bleeding following gentle removal of the scales. A diagnosis of annular plaque–type psoriasis, an uncommon clinical variant of psoriasis, was established based on the chronic course of the disease, characteristic morphology, symmetrical distribution, and positive Auspitz's sign. The patient was treated systemically with methotrexate, which was well tolerated. Significant clinical improvement was observed, with complete resolution of the lesions within 6 months of treatment and no evidence of recurrence at follow-up.

Figure 1.

Symmetrically distributed erythematous annular plaques with fine scaling on the trunk and upper limbs.

Ethical consideration

Patient written informed consent was obtained.

Ethical committee

Comité de Investigación de la UDEM.

Registry number

18092024-CARD-C.