Hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurrent painful nodules, abscesses, draining tunnels, and eventually scarring, particularly in skin folds such as the armpits, groin, genital/perianal area, buttocks, and under the breasts.

HS is not simply a recurrent infection. The current approach considers impaired keratinization and inflammation around the terminal hair follicle as the primary mechanism. Bacteria may play a secondary role; the disease is not caused by poor hygiene and is not contagious.

Typical findings include recurrent painful nodules/abscesses, recurrence in the same areas, discharge, tunneling, and scarring. A history of recurrent "boils," especially in typical fold areas, is important for diagnosing HS.

Genetic predisposition, smoking, obesity, mechanical friction, and hormonal factors may be associated with the disease. None of these alone explains the disease. HS can occur in conjunction with metabolic syndrome, inflammatory bowel diseases, some types of arthritis, depression-anxiety, and hormonal/metabolic conditions.

Diagnosis is clinical and based on lesion type, typical location, and recurrence. Hurley staging assesses structural damage and tunnel/scarring; scores such as IHS4 can be used for quantitative monitoring of inflammatory activity.

Treatment is individualized according to disease activity and permanent structural damage. Topical treatments are used in mild cases, systemic antibiotics for anti-inflammatory purposes in selected patients, and biological therapies in moderate to severe HS. In Europe, biological agents such as adalimumab, secukinumab, and bimekizumab are used in the treatment of moderate to severe HS. Surgical methods such as deroofing or excision may be necessary for persistent tunnels and scar tissue.

Abscess drainage can reduce acute pain but does not eliminate the underlying disease process of HS. Laser hair removal may be helpful in selected patients in the early/mid-stage. In long-standing, severe perianal/gluteal HS, squamous cell carcinoma is a rare but serious complication.