AN EVOLVING DIAGNOSIS OF A DIFFUSE ERYTHRODERMIC RASH

Abstract

Introduction Lymphocytic variant hypereosinophilic syndrome (L-HES) is a rare condition that can be challenging to diagnose. In patients presenting with an erythrodermic skin rash and eosinophilia, it is imperative to review the L-HES diagnostic criteria and periodically reassess for alternative etiologies, particularly with disease progression. Case Description A 39-year-old female presented with a 4-year history of an erythematous, confluent plaque-like rash. Initially, her skin biopsy demonstrated granulomatous dermatitis with necrobiosis but no eosinophils. She had a peripheral absolute eosinophil count of 1100/uL. Her bone marrow biopsy demonstrated a CD4+, CD3-T-cell population with small, non-necrotizing granulomas and no clonal eosinophilia. She was diagnosed with L-HES and started on high-dose glucocorticoids with initial skin improvement; however, skin symptoms subsequently progressed, covering 90% of her body surface area. She was then managed as cutaneous sarcoidosis, but treatment with methotrexate and leflunomide did not improve symptoms. Given her persistent symptoms, she underwent repeat skin biopsy, which demonstrated cutaneous T-cell lymphoma. Symptoms improved with romidepsin. Discussion This patient had initial findings suggestive of L-HES but did not meet L-HES diagnostic criteria. She never had an absolute eosinophil count >1500/uL, nor tissue biopsy demonstrating eosinophil-mediated organ damage. Her disease progression led to re-evaluation and a malignancy diagnosis. Although patients with L-HES can progress to cutaneous T-cell lymphoma, clonal CD4+, CD3- T cells can be found in primary cutaneous T-cell lymphoma without prior HES diagnosis. This case illustrates the importance of continued diagnostic inquiry when the diagnosis is unclear and symptoms progress despite therapy. Lymphocytic variant hypereosinophilic syndrome (L-HES) is a rare condition that can be challenging to diagnose. In patients presenting with an erythrodermic skin rash and eosinophilia, it is imperative to review the L-HES diagnostic criteria and periodically reassess for alternative etiologies, particularly with disease progression. A 39-year-old female presented with a 4-year history of an erythematous, confluent plaque-like rash. Initially, her skin biopsy demonstrated granulomatous dermatitis with necrobiosis but no eosinophils. She had a peripheral absolute eosinophil count of 1100/uL. Her bone marrow biopsy demonstrated a CD4+, CD3-T-cell population with small, non-necrotizing granulomas and no clonal eosinophilia. She was diagnosed with L-HES and started on high-dose glucocorticoids with initial skin improvement; however, skin symptoms subsequently progressed, covering 90% of her body surface area. She was then managed as cutaneous sarcoidosis, but treatment with methotrexate and leflunomide did not improve symptoms. Given her persistent symptoms, she underwent repeat skin biopsy, which demonstrated cutaneous T-cell lymphoma. Symptoms improved with romidepsin. This patient had initial findings suggestive of L-HES but did not meet L-HES diagnostic criteria. She never had an absolute eosinophil count >1500/uL, nor tissue biopsy demonstrating eosinophil-mediated organ damage. Her disease progression led to re-evaluation and a malignancy diagnosis. Although patients with L-HES can progress to cutaneous T-cell lymphoma, clonal CD4+, CD3- T cells can be found in primary cutaneous T-cell lymphoma without prior HES diagnosis. This case illustrates the importance of continued diagnostic inquiry when the diagnosis is unclear and symptoms progress despite therapy.