Associations Between Gout and Acne Keloidalis Nuchae

Acne keloidalis nuchae (AKN) causes red patches on the skin that can develop into papules, plaques, pustules, infections, scarring, and hair loss. The skin disorder, caused by inflammation of the hair follicles typically on the neck and back of the scalp, has a reported incidence between 0.45% and 9%. Treatment for AKN relies on topical and/or intralesional corticosteroids in tandem with antibiotics and surgical therapy.

Another type of chronic inflammation is gout. Gout is chronic recurrent inflammatory arthritis caused by the formation and deposition of monosodium urate crystals around the joints. It manifests as severe bouts of acute painful, redness of the skin, and swollen joints. Gout is predominantly seen in the toe joints, ankles, and knees. Gout is commonly associated with comorbidities such as obesity, cardiovascular disease, hypertension, and type 2 diabetes.

Despite being inflammatory conditions and sharing similar comorbid metabolic profiles, there is little literature establishing an association between AKN and gout. A study published in the Journal of Cosmetic Dermatology investigated whether an association exists between these conditions by assessing the risk of gout in patients with AKN.

Utilizing data from the Clalit Health Services database, researchers conducted a retrospective population-based cohort study. They identified and age-, sex-, and ethnicity-matched 2677 AKN patients with 13,190 control subjects, and the incidence of new-onset gout was compared between cohorts. A multivariate Cox regression model was used to analyze the hazard ratio (HR) for the risk of gout.

Patients with AKN had higher comorbidity rates, with 5.1% of AKN patients having a severe comorbidity compared with 3.9% of control subjects. AKN patients had a higher mean body mass index (BMI) and lower rates of smoking than those in the control cohort. The crude risk of developing gout was significantly higher in AKN patients. Over the course of the study, 17 cases of new-onset gout occurred in AKN patients, and 36 cases occurred in the control group. This resulted in an overall incidence rate of 1.12 and 0.48 per 1,000 person-years among AKN patients and controls, respectively.

When researchers controlled for age, sex, and ethnicity, AKN was found to be an independent risk factor of gout. However, when they controlled for other confounders, such as BMI, diabetes mellitus, hypertension, and dyslipidemia, the risk of gout in AKN patients was not considered statistically significant.

“The risk is more prominent among younger and male patients, and it loses its statistical significance following the adjustment for metabolic confounders,” the authors of the study wrote. “This signifies that although the risk of gout is crudely elevated, it is not thoroughly independent, and it seems to be mediated through metabolic variables.”

The authors suggested that clinicians managing patients with AKN should be aware of the risks and consider previously established prevention methods to manage risk factors of gout. Maintaining awareness of comorbidity may facilitate screening patients for gout and facilitate early detection in AKN patients presenting with suggestive symptoms.