Morphea is an autoimmune connective tissue disorder, which is characterized by the hardening of the skin. It is a relatively uncommon disorder as the annual incidence rate is estimated to be 27 per million; however, the prevalence increases with age. In addition, the disease is more prevalent in females. Although the etiology of morphea is poorly understood, It is thought to be due to several factors, namely genetics such as HLADRB1 ∗ 04:04 and HLA-B37 that increase the susceptibility. Moreover, environmental triggers play a significant role in pathogenesis. All of this will result in T-cell activation, vascular damage, and deposit of fibroblast.
There are three recognized types of the disorder: plaque, linear, and generalized, as shown in the table below.
Morphea is primarily diagnosed clinically, and no further tests are needed to confirm. Blood tests, imaging, and biopsy are used to exclude other diseases. The most prominent biopsy findings of morphea are:
- Overall square punch.
- Epidermal atrophy or loss.
- Dense dermal collagen.
- Lymphocytes and plasma in the subcutaneous layer.
Written By: Dr. Alanoud Hakami, dermatology resident.
Dermatology 4th edition, by Jean L. Bolognia, Julie V. Schaffer, and Lorenzo Cerroni
Fitzpatrick’s Dermatology, Ninth Edition