USMLE Step 1 Question 324

Question:

A mother visits a pediatrician with her two-year-old girl because she has been scratching herself constantly. Physical exam is notable for xerosis, and skin thickening with accentuated skin lines at the neck and hips.

Which of the following statements is most correct?

Correct Answer: B.  The patient has an increased likelihood of developing asthma later in life.

This little girl appears to be suffering from atopic dermatitis, which often presents in the first few years of life, usually manifesting as lichenification (accentuation of normal skin lines with skin thickening). Findings often include xerosis (dry skin) and eczematous lesions. Atopic dermatitis is frequently associated with allergic rhitnitis and asthma. Although patients do not always manifest each part of this “allergic triad,” the patient has an increased likelihood of developing asthma later in life (Choice B) is the best answer.

The mechanism of this pathologic process is well understood (Choice A) is incorrect. Atopic dermatitis is a disease of unknown origin, and the pathophysiology is poorly understood.

The patient has an increased likelihood of developing lupus later in life (Choice C) is incorrect. Atopic dermatitis appears to be an allergic reaction, not an autoimmune process. No association of atopic dermatitis with lupus has been demonstrated.

The patient has come into contact with poison ivy (Choice D) is incorrect. Poison ivy exposure manifests as linear vesicles on erythematous skin.

This pathologic process is usually fatal (Choice E) is incorrect. Although it is a great source of morbidity, mortality due to atopic dermatitis would be unusual.