Differential Diagnosis for Red Rash Covering Face

Single Most Likely Diagnosis

• Acne: This is a common condition, especially in adolescents and young adults, characterized by comedones, papules, pustules, and sometimes cysts, often resulting in a red rash on the face due to inflammation.

Other Likely Diagnoses

• Rosacea: A chronic skin condition that causes redness and acne-like symptoms, often affecting the face. It can be triggered by various factors including sun exposure, stress, and certain foods.
• Eczema (Atopic Dermatitis): Although more commonly associated with dry, itchy skin, eczema can present with redness and rash on the face, especially in individuals with a history of atopic diseases.
• Contact Dermatitis: An allergic or irritant reaction to substances like cosmetics, soaps, or metals, leading to a red, itchy rash on the face.
• Seborrheic Dermatitis: A condition causing scaly patches, red skin, and stubborn dandruff, often affecting oily areas of the body like the face.

Do Not Miss Diagnoses

• Lupus: Systemic lupus erythematosus can cause a characteristic "butterfly" rash across the cheeks and nose, which is a significant diagnostic clue. Missing this diagnosis could lead to delayed treatment of a potentially serious autoimmune disease.
• Cellulitis: A bacterial skin infection that can cause redness, swelling, and warmth, typically on one side of the face. It requires prompt antibiotic treatment to prevent serious complications.
• Erythema Multiforme: An immune-mediated disorder that can be triggered by infections or medications, leading to target-like lesions on the skin, including the face. It can be a sign of a more serious underlying condition.

Rare Diagnoses

• Sarcoidosis: A condition where inflammatory cells form lumps known as granulomas in various parts of the body, including the skin, which can cause rashes, including on the face.
• Kawasaki Disease: Although primarily seen in children, it can cause a fever, rash, and swelling, among other symptoms. It's rare but important to consider due to its potential for serious cardiac complications if not treated promptly.
• Dermatomyositis: An inflammatory disease characterized by skin rash and muscle weakness, with the rash sometimes appearing on the face. It's a rare condition but significant due to its association with underlying malignancies in some cases.