Differential Diagnosis of Psoriasiform Hyperplasia

Key Histopathological Features

• Neutrophil collections in stratum corneum support a psoriasiform process, but can occur in multiple conditions, including psoriasis and pityriasis rubra pilaris 1

Primary Differential Diagnoses

• The American Academy of Dermatology recommends serologic testing (RPR/VDRL and treponemal-specific tests) for symmetric palmoplantar lesions with red-brown macules, to exclude secondary syphilis 3
• Always obtain HIV screening as syphilis and HIV frequently coexist, especially in patients with symmetric palmoplantar lesions 3

Diagnostic Approach

• For palmoplantar lesions, obtain RPR/VDRL, treponemal-specific testing, and HIV screening to exclude secondary syphilis, as recommended by the American Academy of Dermatology 3
• Consider multiple biopsies if diagnosis remains uncertain, as this enhances diagnostic accuracy, according to Praxis Medical Insights 2