granuloma annulare (GA)

Introduction

Self-limited asymptomatic dermatosis characterized by papules in an annular arrangement.

Etiology

• unknown
• may be associated with diabetes mellitus

Epidemiology

• children & young adults
• female:male ratio 2:1

Pathology

• chronic inflammatory & histiocytic infiltration of superficial & mid dermis
• reversible necrobiosis of connective tissue surrounded by palisading histiocytes & multinucleated giant cells
  • degenerating collagen within the dermis
• inflammatory reaction around blood vessels

Clinical manifestations

• generally asymptomatic
• smooth papules or plaques, skin-colored, erythematous or violaceous
• annular or ring-like arrangement
• commonly arises on the dorsal aspect of the hands & feet, elbows & knees, but may appear on other surfaces including the trunk
• case report of symmetric distribution of lesions on trunk, arms, & legs

Laboratory

• serum glucose, hemoglobin A1c to confirm diabetes mellitus
• microscopic examination of KOH preparation of skin scraping

Management

• patient education
  • spontaneous resolution in 75 of cases within 2 years
  • recurrence is common (40%)
• pharmacologic agents
  • topical glucocorticoids
  • intralesional triamcinolone 3 mg/mL
  • hydroxychloroquine
  • glycemic control
• cryotherapy with liquid nitrogen
• PUVA phototherapy

More general terms

• figurate dermatitis (rings, arcs)

Additional terms

• diabetes mellitus
• necrobiosis lipoidica