Abstract
Background: Pityriasis rubra pilaris (PRP) is a rare inflammatory dermatosis that typically presents as follicular and palmoplantar hyperkeratotic plaques with an orange to red-brown scaling, uncommonly evolving to erythroderma. Sezary syndrome (SS) is recognized as the subtype of cutaneous T cell lymphoma which manifests as erythroderma, generalized lymphadenopathy, and the presence of Sezary cells in peripheral blood, lymph nodes, and skin. A clear relationship between PRP and SS has not been well documented. Design: A query of the cutaneous lymphoma registry at a tertiary care center was conducted to search for all cases of CTCL with a history of PRP. Results: Five patients, three males and two females, were identified exhibiting an age range of 51-80 years old at initial PRP diagnosis. All patients initially presented with a pruritic erythema starting on the lower extremities or trunk, with subsequent spread to other areas of the body, eventuating as erythroderma. Four out of five patients failed to respond to multiple topical and systemic treatment regimens. Skin biopsies showed different patterns of parakeratosis, with spongiosis in most cases, psoriasiform hyperplasia in two cases and mild to moderate superficial perivascular lymphocytic infiltrate in all cases. Epidermotropism (lymphocytic exocytosis) was seen in one case, two years before Sezary syndrome was diagnosed. Sezary syndrome was diagnosed between 3 and 6 years following initial diagnosis of PRP. Skin biopsies, correlative T cell receptor gene sequencing, peripheral blood flow cytometry, and lymph node biopsies, were all consistent with SS. Two patients died, two years, and seven years after SS diagnosis, respectively. Conclusion: Pityriasis rubra pilaris and Sezary syndrome, are two rare diseases traditionally thought distinct in nature, but which clinically share an erythrodermic cutaneous presentation. This analysis may offer clues to predictive factors for progression to SS by PRP.
Financial Disclosure:
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