When Rashes Do Not Seem To Respond To Treatment

All of us have experienced a patient whose red, scaly rash has not responded to our prescription topical therapy. Not only is this challenging to us as practitioners but also to the patient. Failure to respond to conventional therapy warrants a skin biopsy.

In these cases, a punch biopsy is an appropriate choice. I have also utilized this procedure in patients who have seen numerous practitioners prior to a visit with me, have a long list of failed medications and have not had a skin biopsy to define the skin condition. In these cases, I choose to perform the skin biopsy prior to initiating any further treatment in order to refine my management plan and reduce the patient frustration of purchasing yet another possible failed therapy.

I do not recommend routine biopsy of all skin rashes. However, if a new onset rash does not correspond to the conventional presentations of psoriasis, eczema and lichen planus, a punch biopsy can be a useful diagnostic tool. In the case of a psoriatic-like plaque, differential diagnoses can range from plaque psoriasis to cutaneous T-cell lymphoma. Treatment plans for these two diagnoses vary in approach and prognosis.

Editor’s note: This blog has been excerpted from Dr. Vlahovic’s upcoming cover story, “When Should You Biopsy?,” which will run in the June issue of Podiatry Today.