Clinicopathological Survey of 204 Rosacea Patients Regarding Rosacea Subgroups and Severity

INTRODUCTION: Few studies have evaluated the histopathological characteristics of clinical rosacea subtypes in detail. OBJECTIVES: To assess rosacea histopathological features in correspondence to clinical subgroups. METHODS: The histopathological findings of 204 rosacea patients were analyzed retrospectively and were compared among clinical subtypes. RESULTS: Thirt-Two Percent of patients were male and 68% were female. Seventy-three patients had erythematotelangiectatic rosacea (ETR) and 110 had papulopustular rosacea (PPR), 12 were ETR + PPR, 4 ocular, 2 phymatous, and 3 had Morbihan’s edema. Perivascular and perifollicular lymphohistiocytic infiltration, perifollicular exocytosis, follicular spongiosis, and ectatic vessels were almost found in all subtypes. Solar elastosis was higher in ETR. Spongiosis, exocytosis of inflammatory cells into epidermis, acanthosis, and granulomatous reaction were higher in PPR. Inflammatory cells exocytosis was more in PPR and phymatous. Demodex folliculorum was identified in 27% of ETR, 33.6% of PPR, 50% of phymatous, one ocular patient, and none of Morbihan edema. Demodex brevis were found in 5% of ETR, 3% of PPR, and 50% of phymatous. Demodex brevis not folliculorum was more in phymatous. Spongiosis was the most common finding in ocular rosacea. CONCLUSIONS: Spongiosis, exocytosis of inflammatory cells, and granulomatous reactions were more in PPR. Solar elastosis was more in ETR. Histopathological findings were compatible with clinical subgroups.