Granuloma Annulare: An Updated Review of Epidemiology, Pathogenesis, and Treatment Options

Tejas P. Joshi; Madeleine Duvic

Disclosures

Am J Clin Dermatol. 2022;23(1):37-50. 

In This Article

Abstract and Introduction

Abstract

Granuloma annulare (GA) is an inflammatory granulomatous skin disease that can be localized (localized GA) or disseminated (generalized GA), with patch, perforating, and subcutaneous subtypes being less common variants of this benign condition. Recently, new research has emerged that further elucidates GA epidemiology and etiopathogenesis; importantly, new therapeutic options for GA have also been described, although there remains a paucity of randomized controlled studies. In this review, we summarize recent updates on GA epidemiology and etiopathogenesis and offer an updated review of the therapeutic options for GA currently reported in the literature. We hope that the current review galvanizes randomized controlled studies that will in turn help lead to the recommendation of evidence-based treatments for GA.

Introduction

The first report of granuloma annulare (GA) is credited to Colcott-Fox, who in 1895 described a 'ringed eruption of the fingers' in an 11-year-old girl.[1] The term 'granuloma annulare' itself was introduced later in 1902 by Radcliffe-Crocker.[2] GA is a condition that remains poorly understood and past attempts to review GA have conceded that the etiopathogenesis eludes facile explanation and that diagnosis and treatment is challenging.[3–7] In 2018, Wang and Khachemoune reviewed literature published up to August 2017 to provide a focused review of therapeutic options for GA. They noted that while localized disease tends to respond well to topical and intralesional corticosteroids, generalized GA remains difficult to manage and refractory to corticosteroid treatment. Furthermore, while they reported phototherapy to be the most well-studied and reliable option for generalized disease, there is otherwise a paucity of evidence-based therapies to establish a paradigm of care for patients with generalized GA.[8]

Just in the past few years, a number of observational studies have been published that shed further light on GA. Additional evidence regarding the mechanism underlying GA has emerged and compelling therapeutic strategies have also been described. Nevertheless, there remains a lack of randomized controlled studies that can establish the efficacy of any particular therapeutic option.

In this review, we briefly discuss new evidence that has emerged regarding GA epidemiology, etiology, and pathogenesis, and provide an updated review of the treatment options currently available for GA. We acknowledge the lack of randomized trials to be a concern and as such we critically appraise the current observational studies for bias and provide the level of evidence available for reviewed treatments. Moreover, as cases of effective treatment lend further support to proposed mechanisms of GA pathogenesis, we also attempt to recapitulate GA pathogenesis vis-à-vis treatment.

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