Perforating Granuloma Annulare — An Unusual Subtype of a Common Disease

Abstract

Perforating granuloma annulare (GA) is a rare subset of GA with an unknown etiology and chronic course. Herein, we report the case of 72 year-old women with a 3-month history of a post-traumatic, persistent, erythematous and exudative plaque located on her left leg. Differential diagnosis included mycobacterial infection, subcutaneous mycosis, perforating dermatoses, pyoderma and squamous cell carcinoma. The histopathology was highly suggestive of a perforating GA. The patient was treated with betamethasone dipropionate cream applied once daily and a complete resolution of the lesion was observed in three weeks. Despite being a very rare subtype of a common disease, perforating granuloma annulare has clinical and histopathological characteristic features that facilitate the differential diagnosis, avoiding unnecessary procedures and inadequate and potentially more invasive treatments.

Perforating Granuloma Annulare Mimicking Psoriasis

“…Since then, it is recognized as a rare subtype of granuloma annulare. Overall pathogenesis of granuloma annulare is thought to be due to a helper T-cell based delayed hypersensitivity reaction to exogenous factors such as minor trauma and ultraviolet radiation [ 2 ].…”

“…Histopathologic features of PGA include granulomas with multinuclear histiocytes arranged in a diffuse or palisading pattern around a trans-epidermal protrusion of necrotic collagen [ 2 ]. The differential diagnosis of PGA most often includes other conditions in which organic material is protruded through the epidermis, such as reactive perforating collagensosis, reactive perforating dermatosis, perforating folliculitis, elastosis perforans serpiginosa, and perforating calcific elastosis [ 2 , 5 ]. PGA is primarily distinguished from other perforating conditions by the presence of granulomas in the dermis.…”

“…PGA is classically described as flesh to red-colored umbilicated papules or pustules ranging from 1-5 mm. These papules often have an overlying scale, crusting, or exudate, and are often arranged in an annular form [ 2 ]. The distribution of PGA can be described as generalized or localized, with only 9% of patients presenting with a single lesion [ 6 ].…”

“…Granuloma annulare (GA) is a benign, granulomatous condition that presents with annular papules on the hands and feet [ 1 ]. One rare subtype of GA is perforating granuloma annulare (PGA), characterized by histopathologic evidence of granulomas surrounding trans-epidermal elimination of necrotic material [ 2 ]. PGA has a typical clinical appearance of umbilicated papules or pustules with crusting [ 2 - 3 ].…”

“…One rare subtype of GA is perforating granuloma annulare (PGA), characterized by histopathologic evidence of granulomas surrounding trans-epidermal elimination of necrotic material [ 2 ]. PGA has a typical clinical appearance of umbilicated papules or pustules with crusting [ 2 - 3 ]. We report an unusual plaque psoriasis-like presentation of localized PGA in a 67-year-old male without systemic symptoms.…”