Metformin as Adjunctive Therapy for Pediatric Patients With Hidradenitis Suppurativa

December 2020 | Volume 19 | Issue 12 | Original Article | 1231 | Copyright © December 2020


Published online November 25, 2020

Christine Moussa DOa, Lisa Wadowski MDb, Harper Price MDa, Lucia Mirea PhDa, Judith O’Haver PhD RN CPNP-PCa

aDepartment of Dermatology, Phoenix Children’s Hospital, Phoenix, AZ
bResidency program, University of Missouri, Columbia MO

Abstract
Background: Hidradenitis suppurativa (HS) is a chronic inflammatory disorder seen in adolescents and adults characterized by abscesses, sinus tracts and scarring, typically affecting intertriginous skin. Treatments often provide suboptimal control of the disease, and there are limited reports of therapies utilized in the pediatric population. There are no published guidelines or consensus for the treatment of pediatric HS.
Purpose: To evaluate the clinical efficacy and safety of metformin as adjunctive treatment in adolescent patients with HS who have not responded to standard therapies at a single institution.
Results: Retrospective chart review identified 16 pediatric patients treated with metformin as adjunctive therapy for HS. Baseline scores were Hurley 1 in eleven (69%) and Hurley 2 in five (31%) patients. Follow-up visit data showed six (67%) patients were Hurley 1 and three (33%) patients were Hurley 2; five patients showed improvement on metformin with decreased frequency of flares, and five patients had no improvement. Six patients were lost to follow up or data was not available. Two patients discontinued metformin therapy due to side effects, including gastrointestinal distress and mood changes; the third patient discontinued due to lack of improvement. Two patients had mildly elevated liver transaminases prior to metformin initiation which improved while on metformin therapy.
Discussion: For some pediatric patients, metformin as an adjunctive therapy may help improve control of HS with minimal side effects. Adequately designed and controlled studies are needed to further evaluate the role of metformin, and efficacy, tolerability and safety in the pediatric HS patients.

J Drugs Dermatol. 2020;19(12):1231-1234. doi:10.36849/JDD.2020.5447

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the follicular unit in intertriginous areas, including the axillae, inguinal and anogenital areas.1 Clinical manifestations include the presence of double-headed comedones, painful nodules that rupture and drain, purulent discharge, sinus tract formation and scarring. HS occurs in approximately 2-4% of the population, predominantly in women (2:1), and often presents in the third decade of life.1-3

Reports of HS in the pediatric population are limited.1,2,4 Approximately 7% of patients have onset of HS before age 13, and 36% of cases present between age 13 and 20 years.1-4 Prepubertal onset is estimated to occur in less than 2% of patients and associated with a more severe course, widespread distribution and higher risk of endocrine abnormalities.3,5 Co-morbidities in pediatric patients include adrenal hyperplasia, premature adrenarche, obesity, precocious puberty and metabolic syndrome.1-3 A positive family history of HS is more commonly reported in childhood-onset disease with an earlier onset of presentation.1,5 The etiology of HS is not well understood. The disease tends to favor apocrine-bearing skin, but histopathological evaluation suggests disease centers around the pilosebaceous unit, with a follicular structure abnormality leading to dilation and rupture of the follicular tract and subsequent inflammatory cascade.6 A genetic predisposition has been considered; impaired notch signaling in hair follicles due to heterozygous mutations in NCSTN, PSEN1 or PSENEN may be significant in the development of the nodules. However, an exact mechanism and relationship with early-onset disease has not been clarified.1,7 A hormonal influence is suggested by the known female preponderance, flares with puberty and menstruation, and association with endocrine abnormalities such as polycystic ovarian syndrome (PCOS) and obesity in some adolescents. HS is most commonly classified according to Hurley stages based on the presence and confluence of nodules, sinus tracts and scars.1,2,8

Treatment of HS is guided by severity and disease progression. There are no established guidelines for pediatric HS; however,