Differential Diagnosis for 26 yo Male Patient with Red Rash
- Single most likely diagnosis
- Pityriasis Rosea: This condition is characterized by a rash that starts with a single, large spot (herald patch) followed by the development of smaller spots, often with a crust in the middle, across the body but typically sparing the face. The size and distribution of the spots, as well as the age of the patient, align with this diagnosis.
- Other Likely diagnoses
- Eczema (Atopic Dermatitis): Could present with red, itchy spots that might crust over, though it often involves the face and typically has a more chronic course.
- Contact Dermatitis: An allergic reaction or irritation from substances like metals, soap, or plants could cause a rash with similar characteristics, depending on the exposure.
- Folliculitis: Inflammation of the hair follicles can cause small, crusty spots, especially if the patient has been shaving or using hot tubs.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningococcemia: Although rare, this condition can present with a petechial or purpuric rash that might initially appear as small red spots. It's a medical emergency due to the risk of sepsis and meningitis.
- Syphilis (Secondary): Can cause a wide variety of rashes, including ones that resemble small, red spots. It's crucial to consider this in the differential due to the potential for serious complications if left untreated.
- Rocky Mountain Spotted Fever (RMSF): Characterized by a rash that can start as small, red spots, this tick-borne illness requires prompt treatment to prevent serious outcomes.
- Rare diagnoses
- Kawasaki Disease: Although more common in children, it can occur in adults and presents with fever, rash, and other systemic symptoms. The rash can be polymorphic and might include small, red spots.
- Sweet Syndrome (Acute Febrile Neutrophilic Dermatosis): Characterized by fever, leukocytosis, and tender, erythematous skin lesions, which can sometimes appear as small, red spots with a crust.