Differential Diagnosis for Maculopapular Rash Involving Palms and Soles
Single Most Likely Diagnosis
- Secondary Syphilis: This is often considered the most likely diagnosis for a maculopapular rash involving the palms and soles due to its classic presentation. Secondary syphilis typically occurs weeks to months after the primary infection and can manifest with a wide range of symptoms, including a rash on the palms and soles, which is a hallmark feature.
Other Likely Diagnoses
- Hand, Foot, and Mouth Disease (HFMD): Caused by viruses such as coxsackievirus A or enterovirus 71, HFMD is characterized by a maculopapular rash on the palms and soles, along with oral ulcers. It's more common in children but can occur in adults.
- Drug Eruptions: Certain medications can cause a maculopapular rash that may involve the palms and soles. Common culprits include antibiotics (like penicillins and sulfonamides), anticonvulsants, and NSAIDs.
- Viral Exanthems: Various viral infections (e.g., measles, rubella, roseola) can cause maculopapular rashes, some of which may involve the palms and soles, although this is less common.
Do Not Miss Diagnoses
- Syphilis (again, due to its importance): Even though listed as the single most likely diagnosis, it's crucial to reiterate the importance of not missing syphilis due to its severe consequences if left untreated, including transmission to neonates and progression to tertiary syphilis.
- Meningococcemia: This condition, caused by Neisseria meningitidis, can present with a petechial or purpuric rash that may initially appear maculopapular and can involve the palms and soles. It's a medical emergency due to the risk of sepsis and meningitis.
- Endocarditis: Infective endocarditis can cause a variety of skin manifestations, including Janeway lesions (macules or nodules on the palms and soles), which are indicative of embolic phenomena.
Rare Diagnoses
- Kawasaki Disease: An acute febrile illness of childhood characterized by inflammation in the walls of medium-sized arteries throughout the body, which can include a rash on the palms and soles among its symptoms.
- Pityriasis Rubra Pilaris (PRP): A rare skin disorder that can cause a maculopapular rash, sometimes involving the palms and soles, along with other characteristic features like palmoplantar keratoderma.
- Erythema Multiforme: While more commonly associated with target lesions, erythema multiforme can occasionally present with a maculopapular rash and may involve the palms and soles, especially in the context of certain infections or drug reactions.