Clinical Pearls & Morning Reports

Posted by Carla Rothaus, MD

Published September 13, 2023


What are some rashes that involve the palms and soles?

The differential diagnosis of rashes that affect the palms and soles is much more limited than that of maculopapular rashes. Read the NEJM Case Records of the Massachusetts General Hospital here.

Clinical Pearls

Q: How does a morbilliform drug eruption typically manifest?

A: A morbilliform (also called maculopapular) drug eruption is the most common drug hypersensitivity reaction. It usually occurs 1 to 2 weeks after exposure to a new drug, but it can occur sooner if the patient has been previously exposed to the drug. Morbilliform drug eruptions tend to occur in a symmetric distribution and often spread in a centrifugal manner, starting on the trunk and spreading out to the arms and legs.

Q: Name two of the most severe cutaneous drug reactions.

A: Among the most severe cutaneous drug reactions are the Stevens–Johnson syndrome and toxic epidermal necrolysis. These conditions are characterized by extensive epidermal necrosis and sloughing and most often involve the mucous membranes in addition to the skin. The Stevens–Johnson syndrome and toxic epidermal necrolysis result in a spectrum of skin abnormalities: skin sloughing occurs in less than 10% of the body-surface area with the Stevens–Johnson syndrome and in greater than 30% with toxic epidermal necrolysis.

Morning Report Questions

Q: Describe the rashes typical of hand, foot, and mouth disease, measles, and Covid-19.

A: Hand, foot, and mouth disease and herpangina are both associated with coxsackievirus infection, and fever and sore throat are common manifestations. The exanthem associated with hand, foot, and mouth disease manifests as painless, nonpruritic, macular, and maculopapular or vesicular lesions on the hands and feet that rarely spread centripetally. The oral lesions associated with hand, foot, and mouth disease are characterized by macules that progress to painful vesicles and finally ulcers. Measles is a morbilliform rash, and lesions usually appear on the head and neck before spreading to the torso and the rest of the body. It is accompanied by fever, cough, coryza, and conjunctivitis. Covid-19 causes a wide variety of cutaneous manifestations, including maculopapular and papulovesicular rashes, chilblain acral lesions (also known as “Covid toes”), vascular necrosis, purpura, petechiae, and livedo-like rashes.

Q: What are some rashes that involve the palms and soles?

A: Patients with subacute bacterial endocarditis can present with petechiae and splinter hemorrhages or with Janeway lesions (erythematous macules on the palms and soles) or Osler nodes (tender, violaceous nodules on the fingers and toes). These characteristics are the result of microvascular occlusion that is either acute or subacute in nature. Toxic shock syndrome can manifest with diffuse, red, macular rashes resembling sunburns on the palms and soles that can progress to desquamation. The most severe cutaneous manifestation of secondary syphilis is an ulcerative skin condition known as lues maligna, but the most common manifestation of secondary syphilis is a diffuse maculopapular rash that classically includes the palms and soles.

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