Can you diagnose this itchy rash?

This 38-year-old female is an insulin dependent diabetic for many years who presents with an itchy rash on her thigh. 

What could be the cause?

A. Linear epidermal nevus.

B. Lichen striatus. 

C. Linear morphea.

D. Herpes zoster.

E. Insulin-induced changes from subcutaneous injections.

(Answer and discussion on next page.)

ANSWER—Case 2: Linear morphea

Rheumatologists diagnose and treat the more severe forms of morphea—linear (C) and generalized. The most commonly prescribed therapy was topical corticosteroids (63%).¹ Dermatologists predominantly prescribed topical treatments or phototherapy (P < .0001, P = .0018, respectively), even to patients with linear and generalized morphea. Therapeutic decision-making is largely determined by the specialty of the provider rather than disease characteristics. Many treatments with little or no proven efficacy are used, whereas others with proven efficacy are underused. Phototherapy, methotrexate/systemic corticosteroids, calcipotriene, and topical tacrolimus have the most evidence for efficacy in morphea. 

Treatment works best in inflammatory disease. Disease activity, severity, progression, and depth should play a role in therapeutic decision-making. ■

Reference:

1.Johnson W, Jacobe H. Morphea in adults and children cohort II: patients with morphea experience delay in diagnosis and large variation in treatment. J Am Acad Dermatol. 2012 Nov;67(5):881-9.