What is linear morphea (localized scleroderma) in children?

From the Guidelines

Linear morphea, also known as localized scleroderma, in children is a rare condition characterized by skin and subdermal tissue involvement, with no internal organ involvement, and is best managed by referral to a specialized pediatric rheumatology center for assessment and treatment. The condition has a female to male ratio of 2.4:1, with a mean age of onset of approximately 7.3 years, and its severity can vary widely from isolated plaques to generalized morphoea and extensive linear lesions involving limbs, trunk, and/or face and head 1.

Key Characteristics of Linear Morphea

• The incidence is 3.4 cases per million children per year, with the linear subtype being the most common 1.
• The condition can start as early as birth, but the mean age of onset is approximately 7.3 years 1.
• The female to male ratio is 2.4:1, indicating a higher prevalence in females 1.

Management Approach

Given the rarity and variability of the disease, management decisions should be based on the particular subtype of disease, the site of lesions, and the degree of activity 1. The recommended treatment approach includes a combination of topical and systemic therapies, with methotrexate at a dose of 15 mg/m²/week being a first-line treatment for active, potentially disfiguring or disabling forms of juvenile localized scleroderma 1. Systemic corticosteroids may be useful in the active inflammatory phase, and their use in combination with methotrexate is supported by evidence 1.

Treatment Recommendations

• Topical treatment with high-potency topical corticosteroids (e.g., clobetasol 0.05% ointment) applied once daily for 4-6 weeks, followed by gradual tapering, can provide immediate local anti-inflammatory effects.
• Systemic treatment with methotrexate at a dose of 15-25 mg/m² weekly, combined with oral prednisone 1 mg/kg/day (maximum 60 mg) for the first 3 months, then tapered over 6-12 months, aims to suppress the underlying autoimmune process and control inflammation.
• Adjunctive therapies such as topical calcineurin inhibitors (e.g., tacrolimus 0.1% ointment) can be used for maintenance therapy or in sensitive areas.
• Physical therapy and occupational therapy should be initiated early to prevent joint contractures and maintain function.
• Regular monitoring of disease activity, including clinical examination and occasionally imaging studies (MRI or ultrasound), is essential to adjust therapy based on clinical response and prevent long-term complications 1.

Safety and Efficacy

The safety and efficacy of methotrexate in the pediatric population have been reported, with a low rate of non-severe side effects, making it a viable treatment option for juvenile localized scleroderma 1. Mycophenolate mofetil may be considered for severe cases or when methotrexate is ineffective or not tolerated, although more trials are needed to establish its safety and efficacy in a larger pediatric population 1.

From the Research

Definition and Characteristics of Linear Morphea

• Linear morphea, also known as linear scleroderma, is a localized form of scleroderma characterized by the presence of lesions that follow a linear distribution pattern 2.
• It is a type of localized scleroderma (LS) or morphoea, which is often considered to be a benign self-limiting condition confined to the skin and subcutaneous tissue, but can lead to significant functional and cosmetic disability 3.
• The disease can affect underlying structures such as muscles and bones, leading to functional limitations 2.

Clinical Presentation and Diagnosis

• The clinical presentation of linear morphea includes band-like distribution, atrophy of underlying tissue, skin sclerosis, and localized loss of body/scalp hair, eyelashes or eyebrows 4.
• Early recognition may be challenging, and extracutaneous manifestations can occur in up to 20% of patients, with arthritis/arthralgia and neurological symptoms being most frequently observed 4.
• Linear morphea can mimic other conditions, such as lichen striatus, and should be excluded during follow-up 2.

Treatment and Management

• Corticosteroids and methotrexate are highly effective as first-line therapy in morphoea, leading to partial reversal of skin manifestations 4.
• Methotrexate (MTX) has been used and documented as a well-tolerated, effective treatment regimen for linear morphea, with or without a short initiation with prednisone therapy 5.
• Baricitinib has also been shown to be a promising treatment option for linear morphea, with remarkable improvement in lesions and no significant disease progression or adverse events 2.
• Long-term monitoring is mandatory due to the risk of relapse after discontinuing therapy, with recurrences common in patients with pediatric-onset morphea 3, 6, 5.