Differential Diagnosis for Rash on Face

• Single most likely diagnosis
  • Acne: This is the most common skin condition affecting the face, characterized by comedones, papules, pustules, and sometimes cysts and nodules. It's often associated with puberty, but can occur at any age.
• Other Likely diagnoses
  • Rosacea: A chronic skin condition causing redness, pimples, and swelling, typically on the face. It's more common in fair-skinned individuals and can be triggered by various factors including sun exposure, stress, and certain foods.
  • Eczema (Atopic Dermatitis): A condition that makes your skin red and itchy, and can appear anywhere on the body, including the face. It's common in children but can occur at any age.
  • Contact Dermatitis: A type of inflammation of the skin that occurs when the skin comes into contact with an irritant or allergen, leading to redness, itching, and small blisters. Common allergens include nickel, fragrances, and certain chemicals in cosmetics.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Lupus: A chronic autoimmune disease that can affect various parts of the body, including the skin, joints, kidneys, brain, and other organs. A characteristic butterfly-shaped rash on the face is a common symptom.
  • Sarcoidosis: A disease characterized by the growth of tiny collections of inflammatory cells (granulomas) in any part of the body — most commonly the lungs and lymph nodes — but can also affect the skin, leading to rashes and lesions on the face.
  • Lyme Disease: An infection caused by the bacterium Borrelia burgdorferi, transmitted to humans through the bite of infected black-legged ticks. An early sign is often a circular rash (erythema migrans) that appears at the site of the tick bite, which can occur on the face.
• Rare diagnoses
  • Sjögren's Syndrome: An autoimmune disorder that primarily affects the glands that produce tears and saliva, but can also cause skin rashes and lesions, including on the face.
  • Dermatomyositis: A rare inflammatory disease characterized by muscle weakness and a distinctive skin rash. The rash can appear on the face, among other areas.
  • Melasma: A condition characterized by patches of discoloration, typically on the face, often associated with hormonal changes and sun exposure. While not rare, it's less common than other conditions listed and can be challenging to treat.