Review Question - QID 212686

This patient has the classic presentation of leprosy (e.g., paresthesia of distal extremities, hairless skin lesions, and skin thickening at the earlobe), which is due to infection with Mycobacterium leprae.

M. leprae is an acid-fast mycobacterium that thrives in cool temperatures. It is endemic in developing areas such as India, Nepal, regions of Africa, and South America. It is worth noting that in the United States, armadillos are the main reservoir. Patients with a high degree of cell-mediated immunity and delayed hypersensitivity present with tuberculoid disease which manifests as well-demarcated skin lesions. Patients with a weak immune response present with a lepromatous response which manifests as a symmetric glove and stocking neuropathy, red skin patches with/without sensory changes, and profound facial deformities (e.g., Leonine facies) secondary to skin thickening, nodular earlobes, and loss of eyebrows/eyelashes. Treatment of tuberculoid disease involves dapsone or rifampin. However, in this patient presenting with lepromatous disease, dapsone, rifampin, and clofazimine are indicated.

Figure A is a clinical image of a lepromatous lesion.

Incorrect Answers:
Answer 2: Hydroxychloroquine is one of the main treatment options for systemic lupus erythematosus, which can also present with skin rash and sensory changes. However, this patient’s skin rashes are more characteristic of leprosy.

Answer 3: Insulin is one of the treatments of diabetes, which, in severe cases, can present with sensory changes secondary to nerve damage. Although this patient has uncontrolled diabetes, it does not explain the characteristic skin lesions and nodular earlobe.

Answer 4: Rifampin, isoniazid, pyrazinamide, ethambutol is the standard treatment for active tuberculosis (TB), which often presents with pulmonary symptoms and fever. This patient is not exhibiting signs of TB.

Answer 5: Terbinafine is one of the treatments for tinea corporis, a fungal infection of the skin. Although the skin lesion can look similar to that of leprosy, tinea corporis does not explain the paresthesia or nodular earlobe seen in this patient.

Bullet Summary:
Leprosy can present with symmetrical paresthesias, skin lesions, and facial deformities; the treatment of choice for lepromatous leprosy is dapsone, rifampin, and clofazimine.