This article is more than 5 years old. Information may no longer be current.

Bimodal distribution found in self-reported onset age of hidradenitis suppurativa

Self-reported age at onset of hidradenitis suppurativa has a bimodal distribution, with peak common onset occurring in the late teens and peak late onset occurring in the mid-40s, according to a retrospective study.

“These findings may help facilitate accurate and timely diagnosis of HS in a previously unrecognized HS subpopulation,” Haley B. Naik, MD, MHSc, of the department of dermatology, University of California, San Francisco, and colleagues wrote in a research letter published in JAMA Dermatology.

Researchers gathered information from 1,203 patients with dermatologist-confirmed hidradenitis suppurativa (HS). Data included age at visit, self-reported age at onset, race, sex, self-identified ethnicity and disease severity.

Age at onset across race, sex and disease severity was compared using Wilcoxon tests, and Cullen-Fry plots were used to identify age at onset as a log-normal distribution, the letter said. Researchers found that sex was significantly associated with onset age, so they used a mixture of regression with sex as a covariate to identify subpopulations.

The study identified two overlapping peaks that comprised a bimodal age at onset distribution, with two subpopulations of onset age centered around two means that differed by sex. HS began in the teen years for the common-onset group (79.2%) and the mid-40s for the late-onset group (20.8%).

Median age at onset was earlier for females than males (19 years vs. 23 years; P < .001). In addition, the age at common onset for females was significantly earlier than that for males (16.8 years vs. 19.7 years; P < .001). Self-identified Hispanic patients had earlier onset ages (18.5 years) than black patients (20 years; P = .03) and white patients (20 years; P = .02).

Researchers noted that recall bias of self-reported age and variable disease duration may be study limitations.

“Despite these limitations, given the overall paucity of data about HS natural history, these findings are an important starting point for future investigation,” they wrote. – by Julia Lowndes

Disclosures: Naik reports she has performed consulting work for 23andMe and is a co-investigator on a grant from AbbVie. Please see the study for all other authors’ relevant financial disclosures.