Making a bad situation worse

Joe R. Monroe, PA-C, MPAS

Mr. Monroe practices in the dermatology department of the Springer Clinic, Tulsa, Okla, and is the founder and presidentelect of the Society of Dermatology Physician Assistants. The author has indicated no relationships to disclose relating to the content of this article. Lieutenant Meehan practices dermatology at Tripler Army Medical Center, Honolulu, Hawaii.

A 59-year-old man was seen by a dermatology PA for evaluation of an itchy rash that began on his leg 2 years previously. He tried a number of topical creams without success until his primary care provider prescribed a cream that combined clotrimazole and betamethasone dipropionate. Even this product never came close to curing the problem, which grew steadily worse, but the cream did relieve the itching. The patient also took oral antibiotics on a number of occasions without success.

The patient had a strong history of atopy manifested by seasonal allergies and reported asthma in childhood. He denied having diabetes. He worked as a truck driver and denied having any pets.

The physical examination revealed a papulosquamous—and in several areas, a papulofollicular, lightly erythematous—process covering a rather large (greater than 15-cm) area of the medial left knee and upper leg (see Figure 1). Several of the papulofollicular lesions were pustular, and annular, scaly lesions were intermixed in the well-defined patch. Potassium hydroxide (KOH) examination of scrapings taken from the pustular lesions showed numerous long, filamentous hyphal elements and no spores.

The name given to this particular clinical picture is

Majocchi's granuloma
Methicillin-resistant Staphylococcus aureus (MRSA) infection
Sporotrichosis
Tinea versicolor

Discussion

The correct answer is Majocchi’s granuloma. This is an iatrogenic, steroid-exacerbated tinea corporis caused by one of the dermatophytes—most commonly Trichophyton rubrum, which normally cannot invade follicles to any clinically appreciable extent. Applying corticosteroids over a long period makes follicular invasion possible by dampening the body’s immune response to fungal infection and has three relevant clinical effects: 1) the infection becomes much harder to diagnose, as happened in this case; 2) the infection becomes more difficult to treat—most cases of Majocchi’s granuloma require systemic as well as topical treatment; and 3) the infection grows steadily larger, which often causes the patient to apply even more medication, thus contributing to a worsening spiral. Majocchi’s granuloma is more common on the lower legs simply because of their proximity to the most common source of fungal organisms (the foot), but the condition can occur on any hairbearing surface.

Majocchi’s granuloma is often misdiagnosed and treated as bacterial infection, and when the condition inevitably fails to respond to treatment, the clinician often assumes it is due to MRSA, another wrong diagnosis. Sporotrichosis and tinea versicolor belong in the differential diagnosis, but a simple KOH test early in the course of this patient’s care would have saved everyone involved a great deal of trouble. So, too, would the observation that application of a potent corticosteroid made the condition worse. Virtually all the prescriptions for this particular combined potent steroid and mediocre antifungal cream are written by nondermatology clinicians. That should tell you something!