The one incorrect statement is choice “a,” since morphea does not progress into systemic sclerosis (SS), although the local histologic process is almost identical in each. Morphea—especially in children, and especially with linear types that course over crucial structures such as joints or faces—can interfere with normal function and growth, making choice “b” correct. Several theories have arisen to explain the genesis of this disease, including an autoimmune basis; to date, none has been proven, so both choice “c” and choice “d” are technically correct.
This case is a perfect example of an established maxim of dermatology: One seldom diagnoses what one has never heard of. The reported incidence of morphea is 25 cases per one million Americans, but it is a common enough complaint in dermatology practices.
Although the precise cause is unknown, there is general agreement that morphea represents localized dysregulation of collagen synthesis and deposition in the dermis. While that process is identical to that seen in SS, the two are otherwise not part of the same clinical continuum—good news for the morphea patient, since SS is a far more serious disease. Morphea patients do not, for example, experience the components of SS such as Raynaud’s phenomenon, sclerodactyly, or involvement of internal organs, nor do they share the potentially dire prognosis of SS patients.
Morphea takes several clinical forms; the most common is the plaque type, which typically presents as an annular lesion on the trunk or extremity, with the potential to grow to considerable size. Most will stop growing in time, but the discolored “burnt-out” lesion remains, leaving a purplish brown atrophic area.
Another form of morphea is a linear configuration. This is seen particularly in children, in whom it can interfere with normal growth and function. Examples include the morphea variants Parry-Romberg syndrome and en coup de sabre; both appear on the face, and deeper structures such as soft tissue and bone can be affected.
This patient has advanced disease, for which calcipotriene cream (to be applied bid for two months) was prescribed, with follow-up to monitor his disease and its effect on the joint as well as the skin. Other medications have been tried for morphea, including minocycline and methotrexate, with decidedly mixed results.