Differential Diagnosis for 18-year-old Male with Rash

Single Most Likely Diagnosis

• Atopic Dermatitis (Eczema): Given the description of red bumps and itching on the face, hands, and ears, atopic dermatitis is a common condition in young adults that matches these symptoms. It often starts on the face and can spread to other parts of the body, including the hands and ears.

Other Likely Diagnoses

• Contact Dermatitis: This condition could be caused by an allergic reaction or irritant exposure, leading to a rash on the face, hands, and ears. The itching and red bumps are consistent with contact dermatitis.
• Seborrheic Dermatitis: Although more common in infants and older adults, seborrheic dermatitis can occur in young adults, causing a rash on the face, particularly in oily areas, and can spread to the ears. Itching is a common symptom.
• Urticaria (Hives): While hives are typically more transient and can appear anywhere on the body, they can cause itching and red bumps, fitting the patient's symptoms.

Do Not Miss Diagnoses

• Lupus: Systemic lupus erythematosus (SLE) can cause a butterfly-shaped rash on the face, and while less common, it can also affect the hands and ears. Itching may not always be present, but the potential severity of lupus makes it a critical diagnosis not to miss.
• Dermatomyositis: This autoimmune condition can cause a rash on the face, hands, and around the ears, often accompanied by muscle weakness. Early diagnosis is crucial for effective management.
• Erythema Multiforme: A skin condition characterized by target lesions, which can appear on the face, hands, and feet. It's often triggered by infections or medications and can be severe.

Rare Diagnoses

• Pemphigus: A group of autoimmune diseases that cause blistering of the skin and mucous membranes. While rare, pemphigus can present with lesions on the face, hands, and ears, and can be life-threatening if not treated.
• Kawasaki Disease: Although primarily seen in children under 5, Kawasaki disease can rarely occur in older children and young adults, causing a rash, among other symptoms like fever and lymphadenopathy.
• Sarcoidosis: A condition that can cause skin lesions, among other systemic symptoms. Skin manifestations can include rashes on the face, hands, and ears, but this would be an uncommon presentation for sarcoidosis in a young adult.