Circumscribed scleroderma is a rare condition involving the localized hardening and thickening of skin and underlying tissues, such as fat, fascia, muscle, or bone. Unlike more widespread forms, it generally does not involve internal organs. The skin changes can vary in appearance and location, often presenting as distinct patches or bands.
Understanding Circumscribed Scleroderma
Circumscribed scleroderma, also known as morphea, is an autoimmune condition involving a localized overproduction of collagen. This causes inflammation that results in fibrosis, or hardening, of the skin and sometimes the tissues directly beneath it. It can occur at any age.
It presents in several forms, each with characteristic appearances and locations. Circumscribed morphea, often called plaque morphea, is the most common type in adults, appearing as one to three oval or round lesions, usually on the trunk or chest. These patches can have a red border and a pale-yellow, thickened center, and they may enlarge when active before flattening. Deep circumscribed morphea extends further into the subcutaneous tissues.
Generalized morphea involves four or more plaques across at least two different anatomical areas, such as the trunk, arms, head, or neck. These patches can be thick and tight, sometimes blending into one another. Linear scleroderma, more common in children, manifests as tight, thick bands of hardened skin. These bands frequently appear on extremities, the back or front of the trunk, buttocks, or face, and can affect underlying bones and muscles, potentially impacting limb development in children.
Diagnosing the Condition
Diagnosing circumscribed scleroderma often begins with a clinical examination of the affected skin. Doctors, frequently dermatologists or rheumatologists, will inquire about symptom onset, progression, and the patient’s medical history. The physical examination focuses on identifying areas of hardened or thickened skin.
To confirm a diagnosis, a skin biopsy is often performed. This procedure involves taking a small sample of the affected skin for microscopic examination, often using a punch biopsy method to obtain a circular tissue sample down to the first layer of fat. The biopsy can reveal signs of fibrosis, or tissue scarring, and excessive collagen in the thickened skin, which are indicators of scleroderma.
While a skin biopsy is valuable, it primarily helps confirm the presence of scleroderma in the sampled tissue and cannot definitively determine if the condition is localized or systemic. Other diagnostic tools, such as blood tests, may also be used to assess immune system activity or rule out other conditions. For instance, an antinuclear antibody (ANA) test is a common blood screening for autoimmune diseases, though a positive result can occur in various conditions and even in healthy individuals.
Managing Circumscribed Scleroderma
Management strategies for circumscribed scleroderma aim to halt disease progression, soften affected skin, and improve cosmetic appearance. Treatment plans are tailored to the individual, considering the type and extent of the condition. Localized skin involvement often responds to topical treatments applied directly to the skin.
Topical corticosteroids and calcipotriene, a form of vitamin D, are commonly used to reduce inflammation and soften the hardened skin. For more widespread or active lesions, phototherapy, which uses specific wavelengths of light, can be beneficial. Ultraviolet A1 (UVA1) phototherapy is often recommended, as it can inhibit inflammatory processes and soften sclerotic skin lesions. Psoralen ultraviolet A (PUVA) treatment is another phototherapy option that involves a light-sensitizing medication followed by UVA light exposure.
For more extensive or progressive cases, systemic medications that affect the entire body may be prescribed. Methotrexate, an immunosuppressive drug, is sometimes used to control inflammation and improve skin fibrosis. Oral corticosteroids may also be employed for their anti-inflammatory effects in situations like inflammatory myositis or refractory arthritis, though their use is generally limited due to potential risks. Mycophenolate mofetil is another immunosuppressant that has shown promise in improving skin fibrosis.
Distinguishing from Systemic Scleroderma
Differentiating circumscribed scleroderma from systemic scleroderma is important because their prognoses and treatment approaches vary significantly. Circumscribed scleroderma, also known as localized scleroderma or morphea, primarily affects the skin and underlying tissues. It rarely involves internal organs, and individuals with this form do not typically develop systemic scleroderma.
In contrast, systemic scleroderma, or systemic sclerosis, is a more complex condition that impacts the skin and can extend to major internal organs, including the gastrointestinal tract, lungs, kidneys, and heart. Skin thickening in systemic scleroderma can be widespread, often affecting the fingers, hands, face, and potentially the trunk and limbs. The involvement of internal organs in systemic scleroderma necessitates a broader and more aggressive treatment approach compared to the localized nature of circumscribed scleroderma. This distinction is important for guiding diagnostic tests, treatment decisions, and understanding the long-term outlook for a patient’s health.