Differential Diagnosis for Flu Rash on Mouth
- Single most likely diagnosis
- Influenza with secondary bacterial infection (e.g., streptococcal pharyngitis): This is a common complication of influenza, where the flu virus predisposes the individual to secondary bacterial infections, which can cause a rash on the mouth.
- Other Likely diagnoses
- Hand, Foot, and Mouth Disease (HFMD): A viral illness characterized by a rash on the hands, feet, and mouth, often caused by coxsackievirus A or enterovirus 71.
- Herpangina: A viral illness caused by coxsackievirus A, characterized by small, painful blisters on the roof of the mouth and the back of the throat.
- Primary Herpes Simplex Virus (HSV) infection: HSV can cause a painful rash on the mouth, lips, and gums, especially in children.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Stevens-Johnson Syndrome (SJS): A rare but life-threatening condition characterized by a severe skin and mucous membrane reaction, often triggered by medications or infections.
- Toxic Epidermal Necrolysis (TEN): A severe skin condition usually triggered by medications, which can cause widespread skin necrosis and detachment.
- Kawasaki Disease: A rare condition that mainly affects children, characterized by fever, rash, and swollen lymph nodes, which can lead to serious cardiac complications if left untreated.
- Rare diagnoses
- Erythema Multiforme (EM): A rare skin condition characterized by target-shaped lesions, often triggered by infections or medications.
- Pemphigus: A group of rare autoimmune diseases that cause blistering of the skin and mucous membranes.
- Aphthous stomatitis: A rare condition characterized by recurrent, painful ulcers on the mouth and lips, which can be triggered by various factors, including infections and autoimmune disorders.