Rosh Emergency Medicine Practice Test

What is the most likely diagnosis for a patient with intensely pruritic, vesicular rash and fever?

1. Contact dermatitis

2. Impetigo

3. Pemphigus

4. Varicella zoster virus

The correct answer is: Varicella zoster virus

A patient presenting with an intensely pruritic vesicular rash and fever is most consistent with an infection caused by the varicella zoster virus, commonly known as chickenpox. This viral infection is characterized by a prodrome of fever and malaise followed by the emergence of a vesicular rash, which initially appears as macules that progress to papules and then vesicles. These vesicles are typically itchy and can become crusted over. The pruritus associated with the vesicular rash is quite pronounced in cases of varicella, leading to significant discomfort for the patient. The systemic symptoms, including fever, are also a hallmark of this infection, reflecting the body’s immune response to the viral pathogen. The other conditions listed do not present with the same pattern of symptoms. Contact dermatitis typically causes localized pruritus and erythema but does not usually present with fever or a vesicular rash as seen in varicella. Impetigo is a bacterial skin infection that may form blisters and crusts but is less likely to cause systemic symptoms like fever to the same extent as varicella. Pemphigus is characterized by intraepithelial blistering but typically does not present with a fever and is associated with an