Differential Diagnosis for a Child with Swollen Neck, Armpits, and Rash on the Face and Armpits

• Single Most Likely Diagnosis
  • Kawasaki Disease: This condition is characterized by fever, rash, swelling of the hands and feet, irritation and redness of the eyes, lips, throat, and tongue. The swollen neck could be indicative of lymphadenopathy, a common feature in Kawasaki disease. The rash and swelling in the armpits could also align with the disease's symptoms, which often include desquamation in the convalescent stage.
• Other Likely Diagnoses
  • Infectious Mononucleosis: Caused by Epstein-Barr virus, it can lead to lymphadenopathy (swollen lymph nodes), which might explain the swollen neck and armpits. A rash can also occur, especially if the patient is taking ampicillin.
  • Scarlet Fever: Although primarily known for its rash and fever, it can also cause lymphadenopathy. The rash typically starts on the chest and armpits before spreading.
  • Allergic Contact Dermatitis: This could explain the rash in the armpits and potentially on the face if the child has come into contact with an allergen. However, it's less likely to cause significant swelling of the neck.
• Do Not Miss Diagnoses
  • Meningitis: Although the primary symptoms are fever, headache, and stiff neck, in severe cases, it could lead to a rash (e.g., in meningococcal meningitis). It's crucial to consider this diagnosis due to its high mortality rate if not promptly treated.
  • Lymphoma: Certain types of lymphoma can present with lymphadenopathy, which might cause swelling in the neck and armpits. A rash could also be present in some cases, especially in cutaneous T-cell lymphoma.
• Rare Diagnoses
  • Juvenile Idiopathic Arthritis (JIA): Some forms of JIA can present with rash and lymphadenopathy, although it's less common.
  • Histoplasmosis: A fungal infection that can cause lymphadenopathy and, in rare cases, a rash. It's more common in endemic areas.
  • Kikuchi-Fujimoto Disease: A rare condition that causes lymphadenopathy, often in the neck, and can be accompanied by a rash and fever. It's more commonly seen in Asian populations.