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.

	Subtype	Location	Symptoms	Picture
Plaque	Plaque	Trunk and proximal Extremities	Erythematous to violaceous patches
	Guttate	Upper half of trunk	Multiple small chalk White Flat
	Atrophoderma of pasini and pierini	Trunk Upper arms	Large (20cm) Brownish-gray hyperpigmented oval atrophic well demarcated plaques Sharp sloping border
	Deep	Involving subcutaneous tissue
	Nodular/ Keloidal		Hyperpigmented sclerotic nodules that mimic keloids
Linear	En coupe de sabre	Frontal, frontoparietal, parasaggital forehead or scalp	Indented appearance
Linear	Parry- Romberg syndrome		Unilateral atrophy of faceà epilepsy, trigeminal neuralgia, and cerebral atrophy
Generalized		Entire trunk and extremities	Widespread indurated plaquesà muscle atrophy and difficulty breathing

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.

Morphea is an incurable disorder; nonetheless, certain medications can help control the disease. These treatments can be divided into topical and systemic. Topical medications include steroids, calcineurin inhibitors, imiquimod, and vitamin A/D analogue. Systemic are corticosteroids, methotrexate, mycophenolate mofetil. For superficial morphea, topical therapies are commonly used. Furthermore, the treatment of choice for moderate to severe morphea is methotrexate, in addition to systemic corticosteroids.

Written By: Dr. Alanoud Hakami, dermatology resident.

References:

Dermatology 4th edition, by Jean L. Bolognia, Julie V. Schaffer, and Lorenzo Cerroni

Fitzpatrick’s Dermatology, Ninth Edition

https://dermnetnz.org