Differential Diagnosis for Redness on Back of Neck and Under Eyebrows

Single Most Likely Diagnosis

• Contact Dermatitis: This is a common condition that can cause redness and inflammation on the skin, especially in areas that come into contact with irritants or allergens. The fact that the redness is localized to the back of the neck and under the eyebrows suggests a reaction to something like hair products, fragrances, or metals in jewelry.

Other Likely Diagnoses

• Seborrheic Dermatitis: This condition causes a red, itchy, and flaky rash, typically on the scalp, but it can also appear on oily areas of the body such as the face, including under the eyebrows. Although the question states the condition is not itchy, seborrheic dermatitis can have varying degrees of itchiness.
• Rosacea: Characterized by redness, pimples, and in some cases, thickened skin, rosacea often affects the face, particularly the forehead, cheeks, and nose, but can also involve the area under the eyebrows. It might not always be itchy.
• Eczema (Atopic Dermatitis): While typically itchy, some forms of eczema might not cause significant itchiness, especially in the early stages or in certain locations on the body. It can appear anywhere, including the back of the neck and face.

Do Not Miss Diagnoses

• Lupus: Systemic lupus erythematosus (SLE) can cause a butterfly-shaped rash across the cheeks and nose, but it can also cause rashes in other areas, including the neck. Although less common, missing lupus could have serious consequences due to its potential to affect multiple organ systems.
• Dermatomyositis: This is an inflammatory disease characterized by skin rash and muscle weakness. The rash can appear on the face, including the eyebrows, and on the neck, often in a V-shape. It's crucial not to miss this diagnosis due to its association with underlying malignancies and autoimmune conditions.

Rare Diagnoses

• Sarcoidosis: A condition that can cause inflammation in various parts of the body, including the skin, lungs, and eyes. Skin symptoms can include rashes and lesions, which might appear on the face and neck.
• Granuloma Faciale: A rare skin condition characterized by single or multiple, reddish-brown, bumps or patches, typically on the face, especially around the eyebrows and forehead. It's not usually itchy but can be persistent.