What could be causing this girl’s discoloration?

A 12-year-old female presented with a worsening discoloring on her trunk of 6 months duration that was asymptomatic. She is otherwise healthy. She is self-conscious about being in a bathing suit. 

What could be causing the discoloration?

A. Vitiligo

B. Morphea 

C. Tinea versicolor

D. Tinea corporis

E. Pityriasis alba

(Answer and discussion on next page)

Answer: Morphea

Morphea, also known as localized scleroderma, is a disorder characterized by excessive collagen deposition leading to thickening of the skin. Etiology is uncertain but thought to be autoimmune. This condition is more common in females and children. Many treatments have been tried with varying success, both topical and oral. 

Vitiligo would be depigmented as opposed to the ivory seen here and would not feel indurated like morphea. Tinea versicolor and corporis typically have scales. Pityriasis alba is hypopigmented, scaly, ill-defined, and not indurated.