Among all patients, the researchers found that left-extremity and extensor-extremity lesions had a stronger association with musculoskeletal involvement (odds ratios of 1.26 and 1.94, respectively). “The reasons for this are unclear,” Dr. Chiu said. “We didn’t assess handedness in our study, but that perhaps could explain it; 90% of the general population is right-hand dominant, so perhaps there’s some sort of protective effect if you’re using an extremity more. Joint contractures showed the greatest discrepancy between left and right extremity. So perhaps if you’re using that one side more, you’re less likely to have a joint contracture.”
When the researchers limited the analysis to head lesions, they observed no significant difference in the lesions between the left and right head (OR, 0.72), but anterior head lesions had a stronger association with neurologic signs or symptoms, compared with posterior head lesions (OR, 2.56), as did superior head lesions, compared with inferior head lesions (OR, 2.23). The association between head lesion location and ophthalmologic involvement was not significant.
“The odds of extracutaneous manifestations vary by site of morphea lesions, with higher odds seen on the left extremity, extensor extremity, the anterior head, and the superior head,” Dr. Chiu concluded. “Further research can be done to perhaps help us decide whether this necessitates difference in management or screening.”
The project was funded by the Pediatric Dermatology Research Alliance and the SPD. Dr. Chiu reported having no relevant financial disclosures.