|
By Kirkland Lau, DO, and Stephen M. Schleicher, MD
|
|
|
CASE:
A 74-year-old woman with a history of hypothyroidism and hypertension presents with an enlarging lesion on her left triceps. The dome-shaped, shiny nodule is 1.2 cm in diameter, with a central keratinous plug. Palpation elicits tenderness. The patient informs you that she was vaccinated for influenza at the exact site of the growth one week before it appeared.
WHAT IS YOUR DIAGNOSIS? |
| |
| |
 |
|
This patient has a keratoacanthoma. These smooth, dome-shaped nodules attain a diameter of 1 to 2 cm and develop a central keratin plug. They most commonly occur on sun-exposed skin in fair-complexioned, elderly patients. Some keratoacanthomas arise in response to ultraviolet light, while others result from trauma, as in this case. The typical rapid growth phase of these lesions is often followed by spontaneous involution months later. Histologically, they are very similar to low-grade squamous cell carcinomas, and most physicians advocate therapeutic intervention. Treatment options include surgery, radiation therapy, and liquid nitrogen cryosurgery. |
|
Dr. Lau is an associate with a division of DermDx Centers for Dermatology in Sinking Spring, Pennsylvania. Dr. Schleicher is director of DermDx Centers and a clinical instructor of dermatology at the Philadelphia College of Osteopathic Medicine, at Kings College in Wilkes-Barre, Pennsylvania, and at Arcadia University in Glenside, Pennsylvania. He is also a member of the EMERGENCY MEDICINE editorial board.
Emerg Med 40(12):23-24, 2008
|
|
