Morphea, also known as localized scleroderma, is a rare skin condition characterized by patches of hardened and discolored skin. It primarily affects the skin, where it can cause inflammation and fibrosis, leading to thickening and hardening. This condition can sometimes extend to the underlying tissues, including fat, fascia, muscle, and even bone. While morphea does not affect internal organs like systemic sclerosis, its visual presentation and progression can vary significantly.
The Hallmarks of Morphea’s Appearance
Morphea lesions often begin as reddish or purplish patches, which may appear oval or round. These initial patches can resemble bruises or areas of inflammation. As the condition progresses, the affected skin becomes firm, thickened, and shiny. The color commonly shifts to an ivory white or yellowish hue at the center of the patch.
The texture of the hardened skin can be smooth, waxy, or bound-down. In some instances, it may develop a “cobblestone” or “orange peel” appearance, particularly when deeper tissues are involved. During the active phase, a violaceous or “lilac ring” often surrounds the central hardened area, indicating ongoing inflammation.
Morphea lesions vary in size, from small spots to large plaques exceeding 20 centimeters. They can be oval or irregular in shape. These lesions frequently appear on the trunk (belly, chest, back), limbs, head, and neck. Hair loss (alopecia) can occur in affected areas due to hair follicle damage.
Variations in Morphea’s Presentation
Morphea manifests in several distinct forms, defined by the distribution and extent of hardened skin patches. Localized morphea, also known as plaque morphea, is the most common type in adults. It presents as one to three isolated, well-defined oval or round plaques, primarily affecting the trunk.
Generalized morphea is a more widespread variant, characterized by four or more indurated plaques, each larger than 3 cm, or involvement of two or more anatomical sites. Multiple lesions may merge, covering larger areas of the body, and can range from hyperpigmented to silvery in color. This form often involves deeper tissues more extensively than localized morphea.
Linear morphea appears as a single band or streak of hardened skin. This linear distribution commonly affects a limb, face, or scalp. A specific presentation on the forehead or scalp, “en coup de sabre” (saber cut), has a characteristic depressed, linear appearance. This variant can resemble a scar.
Pansclerotic morphea is a rare but severe form where the hardening and thickening of the skin are widespread and deep, extending through the subcutaneous fat, fascia, muscle, and sometimes even bone. This extensive involvement can restrict joint movement, making the skin appear bound down and leading to visible contractures. The affected skin may become firm, thickened, dry, and shiny, often sparing the fingertips and toes.
Guttate morphea presents as numerous small, superficial lesions, typically less than 10 mm. These lesions are often whitish or ivory-colored and commonly found on the neck and upper trunk.
Progression and Resolution of Morphea
Morphea lesions change over time as the condition progresses through active and resolution phases. During the active phase, lesions are characterized by ongoing inflammation and hardening, often displaying the violaceous border and central induration. The skin exhibits increased thickness and firmness.
As the inflammatory activity subsides, the hardened skin of morphea lesions may gradually soften. However, the resolution phase often leaves residual changes rather than a complete return to normal skin. A common outcome is post-inflammatory pigmentation, where resolved lesions appear as hyperpigmentation (darkening) or hypopigmentation (lightening), manifesting as brown or white spots and patches.
Another change during resolution is atrophy, where the affected skin may appear thinned, shiny, or depressed. This thinning can make underlying blood vessels more visible. If deeper tissues were involved, a visible indentation or depression might occur due to fat or subcutaneous tissue loss. Damage to hair follicles or sweat glands can also result in hair loss or changes in sweating patterns.