Description

• A benign inflammatory skin disorder leading to excessive collagen deposition with thickening and sclerosis of the skin and subcutaneous tissues with characteristic plaque formation
  • Lesions are well circumscribed, flat, firm to touch, and have a waxy feel. They may be more easily felt than seen, and in initial presentation, itching may occur. They are ivory colored and have a lilac or erythematous halo border.
  • Lesions are not associated with systemic sclerosis (scleroderma) based on lack of sclerosis of fingertips (sclerodactyly), Raynaud phenomenon, and nail fold capillary changes.
• Three phases: active/edematous, inactive/sclerotic/fibrotic, and atrophic lesions
• Morphea is classified into five types (Mayo classification):
  • Plaque: most common subtype especially in adults, well circumscribed, and confined to dermis
  • Generalized: 4+ plaques involving 2+ body sites
  • Bullous: rare
  • Linear: most common subtype in children
  • Deep: more severe and involving all layers from skin to bone, causing limb contractures and muscle atrophy
• Synonym(s): localized scleroderma (LS); scleroderma circumscripta

Epidemiology

Incidence

• Predominant sex: female > male (2.4 to 5:1)
• Peak incidence of plaque subtype in 3rd to 4th decade
• 50% of morphea cases present during childhood.
• Linear morphea can develop before age 10 years in 20% of patients.
• 0.3 to 3.0 cases per 100,000/year

Prevalence

• Onset in children is between ages 2 and 14 years.
• 50 cases per 100,000 at age 18 years
• 220 cases per 100,000 at age 80 years

Etiology and Pathophysiology

• Sclerosis is limited to the skin and systemic sclerosis is absent.
• Biopsy shows lymphocytic perivascular infiltration of the dermis, decreased number of blood vessels, and eccrine (sweat) glands.
• Causation thought to be from vascular damage and enhanced collagen production, although likely with underlying autoimmune etiology
• Drug-induced morphea primarily identified in association with TNF-α inhibitors
• Some association with past trauma, including surgery and vaccination administration, or radiation to the area

Risk Factors

Unknown. Presence of Raynaud phenomenon is a risk factor or marker for possible systemic sclerosis (scleroderma).

Commonly Associated Conditions

• Occurs with slightly greater frequency in those with a personal or family history of autoimmune disorders
• Sometimes associated with other diagnosis, such as arthralgias, carpal tunnel syndrome, Raynaud phenomenon, spina bifida, lichen planus, lichen sclerosis, vitiligo, and alopecia areata