DermaDiagnosis
If at First You Don’t Succeed … Don’t Just Treat Again
A 39-year-old man presents with asymptomatic lesions on both arms. When they manifested about six months ago, the patient diagnosed himself with “...
ANSWERThe correct diagnosis is discoid lupus erythematosus (DLE; choice “c”). For those unfamiliar with DLE, it is often mistaken for the other items listed. Biopsy can distinguish among them.
Fungal infection (dermatophytosis; choice “a”) of the face is unusual and would have responded in some way to the antifungal cream. Likewise, the use of steroid creams would have markedly worsened a fungal infection.
Although this could have been psoriasis (choice “b”), it’s rare for that condition to be confined to the face. It almost always appears elsewhere—the scalp, elbows, knees, and/or nails.
Dermatomyositis (choice “d”), an autoimmune condition, can certainly present with a bimalar rash. However, it is usually accompanied by additional symptoms, such as progressive weakness and muscle pain.
DISCUSSION
DLE can represent a stand-alone diagnosis, or it can be a manifestation of systemic lupus erythematosus (SLE). When present in this bimalar form, the lesions are often mistaken for the “butterfly rash” commonly seen in SLE.
This patient was thoroughly tested for SLE, and no evidence of it was found. Biopsy did, however, show changes consistent with DLE (interface dermatitis with increased mucin formation, among others).
The treatment for DLE is rather simple: It consists of sun protection and oral hydroxychloroquine. This helps reduce inflammation, although the patient will still have residual scarring.
