Differential Diagnosis for a Child with a Swollen Neck, Pain, and Rash Underarms
Single Most Likely Diagnosis
- Infectious Mononucleosis (Mono): This condition, caused by the Epstein-Barr virus, often presents with swollen lymph nodes in the neck, fever, sore throat, and sometimes a rash, particularly if the patient has taken ampicillin. The rash under the arms could be part of a more generalized rash or indicative of another concurrent infection, but mono is a common cause of neck swelling and systemic symptoms in children.
Other Likely Diagnoses
- Strep Throat: Caused by Group A beta-hemolytic streptococci, this infection can lead to swollen and painful lymph nodes in the neck, along with a sore throat and fever. A rash, such as scarlet fever, can also occur.
- Lymphadenitis: Inflammation of the lymph nodes due to a bacterial or viral infection, which can cause neck swelling, pain, and sometimes a rash if the infection spreads or if there's an allergic reaction to the infection.
- Kawasaki Disease: An acute febrile illness that predominantly affects children, characterized by fever, rash, swelling of hands and feet, conjunctivitis, and cervical lymphadenopathy. The rash can appear in various forms and locations, including under the arms.
Do Not Miss Diagnoses
- Retropharyngeal Abscess: A serious infection that can cause severe neck swelling and pain, difficulty swallowing, and breathing problems. It requires immediate medical attention.
- Tuberculosis (TB): Although less common in some regions, TB can cause chronic neck swelling due to lymphadenopathy, and it's crucial not to miss this diagnosis due to its public health implications and the need for specific treatment.
- Lymphoma: A type of cancer that can cause painless swelling of the lymph nodes in the neck, among other symptoms. Early diagnosis is critical for effective treatment.
Rare Diagnoses
- Cat-Scratch Disease: Caused by Bartonella henselae, transmitted through cat scratches or bites, leading to swollen and painful lymph nodes, often in the neck, and sometimes a rash at the site of the scratch.
- Brucellosis: A zoonotic infection that can cause fever, night sweats, and swollen lymph nodes, among other symptoms. It's rare but can be seen in children who have contact with infected animals or consume unpasteurized dairy products.
- Castleman Disease: A rare disorder that involves an overgrowth of cells in the body's lymph nodes, which can cause neck swelling, fever, and rash, among other symptoms.