Differential Diagnosis for Red Bumps Next to the Mouth

Given the symptoms described, here's a structured approach to considering potential diagnoses:

• Single Most Likely Diagnosis

  • Perioral Dermatitis: This condition is characterized by a rash of small, red, and sometimes pus-filled bumps around the mouth. It often worsens over time if not treated and can be triggered by the use of certain skincare products, which aligns with the patient's history of recently stopping all but gentle skincare products.

• Other Likely Diagnoses

  • Contact Dermatitis: An allergic reaction or irritation from a product (even if gentle) could cause red bumps, especially if the patient has recently introduced or continued using a new product.
  • Acne: Although the patient mentions having clear skin, acne can occur at any time and may present as red bumps, especially if the skin is sensitive or if there's an underlying hormonal change.
  • Eczema (Atopic Dermatitis): This condition can cause patches of red, itchy skin and can appear anywhere on the body, including around the mouth.

• Do Not Miss Diagnoses

  • Lupus: Systemic lupus erythematosus can cause a butterfly-shaped rash across the cheeks and nose but can also present with lesions around the mouth. It's crucial to consider this due to its potential for serious systemic complications.
  • Sarcoidosis: This condition can cause skin lesions, including around the mouth, and has systemic implications that require prompt diagnosis and treatment.
  • Infectious Causes (e.g., Impetigo, Herpes Simplex): Bacterial or viral infections can cause red bumps and require specific treatments to prevent spread and complications.

• Rare Diagnoses

  • Granuloma Faciale: A rare skin condition characterized by single or multiple, reddish-brown, bumps on the face, which could potentially appear around the mouth.
  • Sjögren's Syndrome: An autoimmune disorder that can cause skin lesions among other symptoms, though it's less likely to present primarily as red bumps around the mouth.

It's essential to consult a dermatologist for a definitive diagnosis and appropriate treatment, as the condition appears to be worsening. In the meantime, avoiding potential irritants and using gentle skincare products is a prudent approach.