Differential Diagnosis for 28-year-old with Recurrent Facial Rash

Single Most Likely Diagnosis

• Rosacea: This condition is characterized by recurrent episodes of facial flushing, redness, and sometimes acne-like lesions. The symptoms worsen with exercise, heat, and certain products, which aligns with the patient's experience of worsening symptoms when running or exercising and the initial attempts to change personal care products.

Other Likely Diagnoses

• Contact Dermatitis: Despite changing laundry detergents, facial lotions, and toothpaste, the patient could still be reacting to another product or substance not yet identified. The pattern of rash and discomfort, especially noted in the morning and with showering, could suggest a reaction to something in the environment or personal care routine.
• Seborrheic Dermatitis: This condition causes a rash, often on the face, and can be exacerbated by stress, cold weather, and certain products. The description of the rash and its recurrence could fit this diagnosis, especially if the patient has not considered all potential irritants.
• Eczema (Atopic Dermatitis): Although less common in adults without a previous history, eczema can cause facial rashes and is exacerbated by heat, stress, and certain products. The sensation of "a thousand needles" could be indicative of the intense itching associated with eczema.

Do Not Miss Diagnoses

• Lupus: Systemic lupus erythematosus (SLE) can cause a butterfly-shaped rash across the cheeks and nose, which could be mistaken for other conditions. Although less likely given the information, missing a diagnosis of lupus could have serious consequences due to its potential to affect multiple organ systems.
• Sarcoidosis: This condition can cause skin lesions and rashes, among other symptoms. It's crucial not to miss this diagnosis due to its potential to affect the lungs and other organs.

Rare Diagnoses

• Demodex Folliculitis: Caused by a mite that lives in hair follicles, this condition can lead to facial rash and rosacea-like symptoms. It's less common but could be considered if other diagnoses are ruled out.
• Granuloma Faciale: A rare skin condition characterized by persistent, single or multiple, erythematous to purple plaques and nodules, typically on the face. It's an unlikely diagnosis but should be considered in the differential for recurrent, unexplained facial rashes.