Histopathological Features and Differential Diagnosis of Pityriasis Lichenoides Et Varioliformis Acuta: A Retrospective Study of 12 Cases.

OBJECTIVE

This retrospective study aimed to describe the clinicopathological features of pityriasis lichenoides et varioliformis acuta (PLEVA) in a cohort of 12 patients, to evaluate the correlation between clinical morphology and key histopathological findings, and to assess the diagnostic utility of these features for improving differential diagnosis from its main mimics.

METHODS

Twelve patients with biopsy-proven PLEVA were seen in our dermatology department between June 2023 and October 2025. Slides were reviewed by two senior dermatopathologists independently, without prior knowledge of the presumptive diagnosis; final diagnoses were confirmed through clinicopathological correlation. Key histopathological features and differential diagnoses were reviewed against the published literature.

RESULTS

The patients included nine males and three females (male-to-female ratio 3:1), with a mean age of 23.5 ± 8.5 years (range 11-37 years). Lesions presented as scattered erythematous to brown papules with adherent scales or crusts; central necrosis was observed in five cases (42%). Histopathological analysis revealed hyperkeratosis, basal cell liquefaction degeneration, and superficial perivascular/interface lymphocytic infiltration in 100% of cases. Parakeratosis was noted in 92%, spongiosis in 67%, extravasated erythrocytes in 75%, and pigment-laden macrophages in 42%. No leukocytoclastic vasculitis or Pautrier microabscesses were identified. Clinical and histological findings correlated well in most cases; in one atypical case presenting only with brown macules, the clinical history was essential for reaching the correct diagnosis.

CONCLUSION

PLEVA is marked by prominent interface dermatitis and extravasation of erythrocytes. A thorough clinicopathological correlation is essential to differentiate it from various other inflammatory and lymphoproliferative dermatological conditions.