Differential Diagnosis for Macules on Palms and Soles

The presence of macules on the palms and soles, similar to those seen in hand, foot, and mouth disease (HFMD), can be caused by various conditions. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Hand, Foot, and Mouth Disease (HFMD): This is the most likely diagnosis due to the characteristic distribution of macules on the palms and soles, often accompanied by fever, sore throat, and oral ulcers. HFMD is commonly caused by coxsackievirus A or enterovirus 71.

• Other Likely Diagnoses

  • Secondary Syphilis: This condition can cause maculopapular rashes on the palms and soles, among other symptoms like fever, lymphadenopathy, and oral ulcers. The rash in secondary syphilis is often more widespread and can be accompanied by other systemic symptoms.
  • Kawasaki Disease: Although more commonly associated with children, Kawasaki disease can present with rash, fever, and desquamation of the hands and feet, which might resemble the macules seen in HFMD.
  • Enteroviral infections (other than HFMD): Other enteroviruses can cause similar rashes and symptoms, making them part of the differential diagnosis based on clinical presentation and epidemiological factors.

• Do Not Miss Diagnoses

  • Meningococcemia: This is a life-threatening condition caused by Neisseria meningitidis, which can present with a petechial or purpuric rash that might initially appear as macules. It's crucial to consider this diagnosis due to its high mortality rate if not promptly treated.
  • Rocky Mountain Spotted Fever (RMSF): Caused by Rickettsia rickettsii, RMSF can present with a rash that starts as macules and progresses to petechiae, often involving the palms and soles. It's essential to recognize RMSF early due to its potential severity.

• Rare Diagnoses

  • Pityriasis Rubra Pilaris (PRP): A rare skin disorder characterized by constant scaling, red-orange palmoplantar keratoderma, and sometimes maculopapular eruptions. While it's less likely, PRP could be considered in the differential for its involvement of the palms and soles.
  • Erythema Multiforme: Although it typically involves the hands and feet less frequently than other areas, erythema multiforme can present with target lesions that might be confused with macules, especially in its early stages.