Rosacea: a clinicopathological approach

There are few reports of the histological changes in rosacea, and little attempt has been made to correlate such changes with clinical findings. In the present study, we describe in detail the histopathological features of rosacea in a large number of patients and simultaneously investigate the aetiopathogenesis of the disease based on the comparative assessment of epidemiological, clinical and histological findings.

The study included 73 patients with rosacea. A skin biopsy with a 4-mm punch was performed in each case. All biopsy specimens included subcutaneous tissue. In 10 randomly selected patients, facial biopsy specimens were obtained from both involved and uninvolved (non-lesional) skin. Demodex mite presence was estimated semi-quantitatively under light microscopy. Patients with self-reported gastro-intestinal symptoms were submitted to upper gastro-intestinal endoscopy, and a rapid urease test was performed. Serological antibodies, IgG and IgA, against Helicobacter pylori were also detected.

The patients had a broad clinical spectrum of lesions. No specific histological features associated with either erythematous-telangiectatic or papulopustular clinical forms were noticed. Histological examination showed that there is no histological pattern unique to rosacea. Three different types of granulomas were observed: small palisaded ones around altered collagen and other granulomas of elastolytic and non-specific epithelioid type, all coexisting in 5 cases. The deep dermis and subcutis were frequently involved. Comparative study in 10 rosacea patients between lesional and non-lesional skin biopsies revealed almost the same histological changes to the latter biopsies, to a lesser degree though.

Rosacea seems to be a reaction pattern to which a variety of pathogenetic routes may lead.