How would you diagnose this persistent itchy rash?

A 50-year-old female presented for evaluation of a 10-year history of an itchy rash that failed to respond to topical and systemic steroids. She is otherwise healthy. Biopsy in the past was non-specific. The rash was along the waistline and sides of the trunk.

What is your diagnosis? 

A. Mycosis fungoides. 

B. Confluent and reticulated papillomatosis. 

C. Tinea corporis.

D. Parapsoriasis. 

E. Livedo reticularis.

(Answer and discussion on next page)

Answer—Mycosis fungoides

The average time between onset of skin symptoms to diagnosis is 6 years. Early in the course, the skin lesions and the biopsy results are non-specific. The condition is often confused with eczema and neurodermatitis. Practitioners must obtain repeated biopsies in order to make a diagnosis.

In terms of presentation, the initial patch stage typically lasts for years. Sometimes, these patches have a thin, wrinkled quality—often with reticulated pigmentation. In this stage, pruritus is usually minimal or absent.  ν