Differential Diagnosis for Raised Erythematous Maculopapular Rash in an HIV Positive Patient on Dapsone

• Single Most Likely Diagnosis
  • Dapsone hypersensitivity reaction: This is a common adverse effect of dapsone, especially in the initial stages of treatment. The reaction can manifest as a maculopapular rash and is more likely in patients with HIV due to their compromised immune status.
• Other Likely Diagnoses
  • Drug rash due to other medications: HIV patients are often on multiple medications, and any of these could potentially cause a drug rash. Common culprits include antiretroviral therapies, antibiotics, and other medications used to treat opportunistic infections.
  • Infections (viral, bacterial, or fungal): Given the patient's immunocompromised state, infections that could cause a rash, such as varicella-zoster virus, herpes simplex, or fungal infections like dermatophytosis, should be considered.
  • Eosinophilic folliculitis: This condition is more common in HIV-positive individuals and can present with a maculopapular rash, particularly on the trunk and extremities.
• Do Not Miss Diagnoses
  • Stevens-Johnson Syndrome (SJS) or Toxic Epidermal Necrolysis (TEN): Although less common, these severe skin reactions can be life-threatening and are associated with medication use, including dapsone. Early recognition is crucial for management and preventing significant morbidity and mortality.
  • Disseminated infections (e.g., tuberculosis, histoplasmosis): In HIV-positive patients, systemic infections can manifest with skin rashes. These conditions require prompt diagnosis and treatment to prevent severe outcomes.
• Rare Diagnoses
  • Cutaneous lymphoma: While rare, HIV-positive patients have an increased risk of developing lymphomas, including those that manifest in the skin.
  • Kaposi's sarcoma: This is a type of cancer that can cause skin lesions and is more common in HIV-positive individuals, especially those with advanced immunosuppression.