Differential Diagnosis for 33-year-old Female with Possible Abscess on Right Upper Back
- Single most likely diagnosis:
- Folliculitis or Furuncle: Given the description of a small pimple-like lesion on the right upper back, which is unable to be incised and drained (I&D), folliculitis or a furuncle (boil) are the most likely diagnoses. The patient's history of recurrent infections, including tonsillitis and the presence of an abscess under her left axilla, suggests a propensity for skin and soft tissue infections.
- Other Likely diagnoses:
- Cellulitis: The patient's symptoms of feeling ill, chills, and the presence of a skin lesion could also suggest cellulitis, an infection of the skin and subcutaneous tissues.
- Abscess: Although the lesion on the right upper back is described as a small pimple and unable to be I&D, it's still possible that it could be a small abscess, especially given the patient's history of abscess formation.
- Staphylococcal or Serratia infection: Given the patient's previous culture results showing moderate Serratia and methicillin-susceptible Staphylococcus aureus, it's possible that the current lesion could be infected with one of these organisms.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Endocarditis: Although less likely, given the patient's history of recurrent infections and potential for bacteremia, endocarditis is a diagnosis that should not be missed due to its high mortality rate if left untreated.
- Osteomyelitis: If the infection has spread to the bone, osteomyelitis could be a possibility, especially if the patient has been experiencing systemic symptoms like chills and feeling ill.
- Septicemia: The patient's history of recurrent infections and current symptoms of feeling ill and chills raise the concern for septicemia, which would require prompt diagnosis and treatment.
- Rare diagnoses:
- Hidradenitis Suppurativa: Although the patient has a history of an abscess under her left axilla, hidradenitis suppurativa is a less likely diagnosis given the lack of other characteristic symptoms like chronic skin lesions and scarring in the apocrine-gland-bearing areas of the body.
- Actinomycosis: This is a rare bacterial infection that can cause abscesses and sinus tracts, but it is less likely given the patient's presentation and lack of other characteristic symptoms like a history of oral surgery or dental procedures.