Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by inflammatory nodules, abscesses, recurrent furuncles, and fistulas in the axillae, groin, perianal, or inframammary regions. It significantly affects quality of life and can cause depression and anxiety.1 Treatment is complex and often unsatisfactory. Treatments used include antibiotics, topical or systemic corticosteroids, classical immunosuppressants, tumor necrosis factor α (TNFα) inhibitors (e.g. adalimumab), antiandrogens, antidiabetics such as metformin, and surgical procedures. Nonpharmacological interventions such as dietary supplements can be indicated, although evidence supporting their utility is scarce (Table 1).2

A recent retrospective study, which included 92 patients with mild-to-moderate HS successfully treated with oral tetracyclines, evaluated the utility of oral zinc gluconate (ZnG) (90mg/d) and nicotinamide (30mg/d) as maintenance treatment for 90 days in 47 patients versus 45 untreated control patients. Significant decreases were observed in the treated versus the control group at weeks 12 and 24 in the following parameters: lesion severity, according to the International Hidradenitis Suppurativa Severity Score System (4.0 and 4.7 versus 6.2 and 7.8, respectively); quality of life according to the Dermatology Life Quality Index (2.9 and 3.5 versus 7.5 and 10.6, respectively); pain (mean visual analog scale score of 2.0 and 2.4 versus 7.5 and 10.6, respectively); and mean duration of flares (3.8 and 4.9 d versus 5 .6 and 8.9 d, respectively). Mean disease-free survival was also significantly longer in the treated group (20.4 d versus 5.4 d in the control group). All these differences were statistically significant (P<0.005). Reported adverse effects consisted of nausea in 2 patients, neither of whom discontinued treatment.3

Two previous studies also support the utility of ZnG in HS. The first pilot study4 included 22 patients with HS refractory to conventional treatment, treated with 90mg/d ZnG. All individuals showed an improvement, either partial (63.6%) or complete (36%). Adverse effects were observed in only 3 patients. Another study5 evaluated the efficacy of ZnG and topical 2% triclosan in 66 patients with mild-to-moderate HS, and reported a significant improvement at 3 months in disease severity, the number of inflammatory nodules and flares, and in quality of life. Gastrointestinal adverse effects were observed in 22 individuals, of whom 5 discontinued treatment. The beneficial effects of ZnG in HS and in other dermatoses may be explained by its anti-inflammatory activity: it inhibits neutrophil chemotaxis, activates natural killer cells and phagocytes, regulates the expression of integrins in keratinocytes, and modulates the production of proinflammatory cytokines, such as TNFα and interleukin 6.4 Nicotinamide also has anti-inflammatory and antioxidant properties and decreases the accumulation of free radicals.

Management of HS is complex and nonpharmacological interventions can be particularly useful. The combination of ZnG and nicotinamide is a low-cost and well-tolerated alternative, and may be useful as a maintenance treatment or as an adjunct to conventional therapy.