Study Reports on US Incidence, Prevalence of Granuloma Annulare

Data from the large-scale, population-based study corroborate previous single-center study findings.

A new cross-sectional study detailed the prevalence of granuloma annulare in the United States, providing insight into its epidemiology and incidences.

Few large-scale population-based studies have explored the prevalence and incidences of the rare disease, and the burden of it has not been well-established.

As such, a team led by John Barbieri, MD, MBA, of the University of Pennsylvania Perelman School of Medicine, utilized ICD-10 codes to assess patient data from the Optum Clinformatics Database between January 1, 2017-December 31, 2018.

“The Optum Clinformatics Data Mart includes deidentified commercial claims data for approximately 18 million to 20 million covered individuals in the United States annually,” they noted.

The Study

The team thus gathered demographic and clinical data from 11,608 patients with incident granuloma annulare as well as 17,862 patients with prevalent granuloma annulare. Among those with incident disease, 74.8% were female, and the mean age was 56.5 years.

Of those with prevalent granuloma annulare, 75.8% were female, and mean age was 56.6 years.

Thus, the overall annualized incidence was 0.04%, or 37.9 per 100,000 (95% CI, 36.9-38.9) person-years. The overall annualized prevalence was 0.06%, or 58.3 per 100,000 (95% CI, 57.1-59.5) person-years.

Barbieri and colleagued noted that the overall incidence of granuloma annulare was higher among women (female to male ratio, 2.8:1; P<.001) and in those in the 5th decade of life.

The incidence for those between 50-59 years old was 58.6 per 100,000 (95% CI, 55.2-62.0) person-years—compared to 34.6 per 100,000 (95% CI, 31.9-37.2) person-years among those 40 -49 years of age and 23.1 per 100,000 person-years (95% CI, 21.0-25.3) for those 30-39 years of age (P < .001).

Furthermore, incidence was higher among White patients (48.2 [95% CI, 46.8- 49.7]) than Black patients (21.3 [95% CI, 18.8-23.9]; P < .001).

The investigators also reported that prevalent granuloma annulare was higher among women as well (female to male ratio, 3.0:1; P<.001). 

Similar to incident disease, prevalence was higher among those in the fifth decade of life (91.5 per 100,000 [95% CI, 87.3-95.8] person-years) and White individuals (72.7 [95% CI, 70.9-74.4]).

“Within 6 months of their first diagnosis, 4822 patients (41.5%) filled a prescription for a topical corticosteroid, and 1087 patients (9.4%) received an intralesional injection,” they wrote. “Within 6 months of their first diagnosis, oral tetracycline-class antibiotic prescriptions were filled by 820 patients (7.1%), and hydroxychloroquine prescriptions were filled by 268 patients (2.3%).” 

Frequencies of treatment use were similar at month 12, the investigators noted. Phototherapy, dapsone, systemic retinoids, and TNF inhibitors were rarely used as therapies.

Patients also rarely presented to the clinician with other inflammatory skin disorders—such as acne (2.4%) psoriasis (1.2%), and atopic dermatitis (1.7%)—within 3 months prior to or following first diagnosis of granuloma annulare.

“These findings provide important background regarding the basic epidemiology and over- all burden of granuloma annulare in the United States,” Barbiere and colleagues wrote. “Future studies are needed to better understand the association of granuloma annulare with quality of life and the most optimal treatment approaches for this condition.”

The study, “Incidence and Prevalence of Granuloma Annulare in the United States,” was published online in JAMA Dermatology.