Is this painful swelling a spider bite?

November 10, 2010

For 5 days, a 68-year-old woman has been bothered by a painful swelling on her left cheek. There is no history of trauma or bite. She takes a diuretic for mild hypertension. Amoxicillin/clavulanate was started 2 days earlier pending the results of a bacterial culture.What is the likely diagnosis?

For 5 days, a 68-year-old woman has been bothered by a painful swelling on her left cheek. There is no history of trauma or bite. She takes a diuretic for mild hypertension. Amoxicillin/clavulanate was started 2 days earlier pending the results of a bacterial culture.

What is the likely diagnosis?

A. Brown recluse spider bite.

B. Herpes zoster.

C. Herpes simplex.

D. Sarcoidosis.

E. Erysipelas.

(Answer on next page)

Dermclinic–Answers

Case 2: Erysipelas

The bacterial culture grew group A β-hemolytic streptococci, confirming the suspected diagnosis of erysipelas, E. This eruption is characterized by the sudden onset of erythema; heat; swelling; and a raised, indurated plaque. Patients often complain of fever and chills. This patient completed the 10-day course of antibiotics; her recovery was uneventful.

Herpes simplex and herpes zoster feature grouped vesicles on an erythematous base. Sarcoidosis does not present acutely with pain. Unlike the eruption seen here, spider bites usually have a necrotic center.