Differential Builder Helps Physician Dx Unusual Rash Presentation

Moshe K., an attending physician at Parcare Community Health Center, shares how building a differential in VisualDx helped him make a diagnosis:

“I had a case with a 3-year-old child with an unusual rash; a cross between herpes and coxsackie virus. I was able to put in the demographic information, lack of fever, location, and general appearance, took a picture of the rash, and out popped the ddx with likelihood. It was very useful because it added some diagnoses to the ddx that I wasn’t thinking of and I was able to diagnose atypical coxsackie virus infection.”

What is coxsackie viral infection?

The coxsackieviruses are members of the genus Enterovirus and are responsible for a variety of clinical diseases in humans. The most common clinical presentation is an undifferentiated febrile illness.

Coxsackieviruses are frequently associated with rashes. The rash is usually not specific enough to allow a clinical diagnosis. One exception is hand-foot-and-mouth disease, which can be caused by certain coxsackievirus serotypes, most commonly A16. This disease is most prevalent in children younger than 10 years. Patients have sore throat and fever. Vesicles are present in the oral cavity. Vesicular and papular lesions are also seen on the extensor surfaces of the hands and feet.

What should we be aware of when making a diagnosis?

The classic manifestations of hand-foot-and-mouth disease include oral ulcerations and vesicular exanthema on the palms and soles of hands and feet.

Some atypical presentations of coxsackievirus infection include:

• Nail changes – Beau lines (horizontal ridges of the nail plate) or onychomadesis (separation of proximal nail from the nail bed)
• More extensive distribution of rash involving the trunk and extremities
• Eczema coxsackium, resembling eczema herpeticum, found in certain patients with atopic dermatitis
• Hemorrhagic findings of petechiae or purpura

How can we treat this?

The mainstays of therapy are adequate hydration and management of pain. Pain may be managed with NSAIDs. Topical analgesics are not recommended and may even cause harm (due to toxicity and allergic reactions).