Progressive Symmetrical Erythrokeratoderma-Like Psoriasis: A New Case Report

Background: Psoriasis, a chronic, systemic, inflammatory disease with prominent skin involvement, affects approximately 2% - 4% of the world population. Common variants of psoriasis are plaque psoriasis, inverse psoriasis, guttate psoriasis, erythrodermic psoriasis, pustular form either palmoplantar pustular psoriasis or generalized pustular psoriasis, nail psoriasis, and psoriatic arthritis. Progressive Symmetrical Erythrokeratoderma (PSEK) is a rare genetic disorder, characterized by fixed, well-defined erythematous and hyperkeratotic plaques distributed predominantly on the elbows, knees, trunk, and dorsal surfaces of hands and feet. Clinically has the same presentation to psoriasis especially at early onset and could be confused with psoriasis but histopathological findings and progression of the psoriatic disease can differentiate between both conditions. Aim: To document a new variant of a severe, recalcitrant type of psoriasis with a history of recurrent attacks of exacerbations and partial remissions especially in lesions involving lower extremities that are clinically PSEK-like in presentation, but histopathologically consistent with psoriasis. Case report: A 12-year-old childhood male, known case of Down’s syndrome, presented to our clinic with a history of severely pruritic skin rashes involving the perioral area, corners of the mouth, bilateral elbows, dorsal hands, scrotum, and both lower extremities for 6 years duration. The rashes gradually progressed with time to form fixed lesions in the last 2 years. He was received multiple treatment modalities, including topical steroids, topical vitamin D derivatives, and narrowband UVB phototherapy without significant improvement and the lesions became more worsened over time. Conclusion: psoriasis can be presenting with a new variant of a severe, recalcitrant, and difficult to treat type in Down syndrome cases with a history of recurrent attacks of exacerbations and partial remissions especially in lesions involving lower extremities which are clinically PSEK-like in presentation, but histopathologically consistent with psoriasis. However, early diagnosis and strict management are important in controlling the severity of the condition.