Pediatric morphea lesion location may give clues to extracutaneous manifestations

Pediatric morphea lesions are not distributed randomly, and the location on the body can help clinicians understand extracutaneous manifestation risk factors, according to a study.

“Morphea is a poorly characterized disorder with unclear pathogenesis,” Yvonne E. Chiu, MD, of the departments of dermatology and pediatrics, section of pediatric dermatology, Medical College of Wisconsin, and colleagues wrote. “It can develop at any body site, but the distribution pattern of morphea lesions on the body has not been fully elucidated.”

A retrospective cross-sectional study used clinical photographs of morphea lesions from 823 patients. A total of 2,522 lesions were mapped onto body diagrams.

Morphea subtypes of plaque, linear, generalized or mixed were identified, as were musculoskeletal complications including arthritis, arthralgias, joint contractures and leg length discrepancy. MRI of the brain, CT of the head, EEG and other neurological tests were also categorized.

The trunk was the most common site for lesions (1,184, or 46.9%), with the neck having the fewest lesions (108, or 4.3%).

The head and neck were most likely to have linear morphea, while plaque and generalized morphea were more likely to be on the trunk.

Extracutaneous manifestations were reported in 339 patients (41.2%).

Neurologic manifestations were mostly non-migraine headaches, migraine headaches and seizures, while arthralgia, joint contracture, limb length discrepancy affecting function and limb asymmetry were the most common musculoskeletal effects.

Musculoskeletal complications were more likely when lesions had extensor extremity involvement (OR = 2.0; 95% CI, 1.2-3.4). When both extensor and flexor extremities were affected, the likelihood rose (OR = 4.7; 95% CI, 2.5-8.9 compared with flexor only; OR = 2.3; 95%, CI 1.5-3.5 compared with extensor only).

When lesions were on the anterior head, neurological symptoms were likely than those on the posterior head (OR = 2.8; 95% CI, 1.7-4.6), as well as when on the superior head compared with the inferior head (OR = 2.3; 95% CI, 1.6-3.4).

“This study more finely characterizes the distribution of pediatric-onset morphea, demonstrating that morphea lesions disproportionately affect certain body sites,” the authors wrote. “The differences in morphea distribution may provide clues to its pathogenesis.”