Bacteriology of hidradenitis suppurativa exacerbations and deep tissue cultures obtained during carbon dioxide laser treatment

Summary Background Previous studies have shown different bacteria in hidradenitis suppurativa (HS) lesions, but the literature regarding bacteria in acute exacerbation of HS is sparse. Objectives To determine the type of bacteria isolated from HS lesions during exacerbations of the disease. Methods Patients with HS with acute nodules or abscesses were examined and treated by carbon dioxide laser vaporization. Bacterial samples for aerobic and anaerobic cultures were taken from the skin surface (before surgery) and then from the deeper layers (during surgery) of the lesions. At each level two samples were taken, one with a punch biopsy and one by pressing a soft agar gel against the skin. The bacterial findings were typed and quantified. Results A total of 10 patients (eight women and two men), with a mean age of 37·2 years and a mean HS duration of 14·5 years, were included. All of them had an ongoing exacerbation (mean duration 5·6 days) of their HS, with one inflamed lesion that was treated by carbon dioxide laser vaporization. Coagulase‐negative staphylococci (CNS) were found in the deep layers in all 10 patients. Nine of the patients carried Corynebacterium spp. and two alpha‐haemolytic streptococci at various levels. Among the anaerobic microorganisms, Gram‐positive cocci were the most common bacteria. Conclusions As found in a previous study, CNS were the most common bacteria, but contrary to what we expected, Staphylococcus aureus was not found in any cultures from acute inflammatory nodules of HS exacerbations.