Differential Diagnosis for Itchy Scalp

• Single most likely diagnosis
  • Dandruff (seborrheic dermatitis): This is the most common cause of an itchy scalp, characterized by flakes of skin on the scalp, often accompanied by redness and irritation. It's a chronic condition that can be managed with over-the-counter shampoos and good scalp hygiene.
• Other Likely diagnoses
  • Psoriasis: An autoimmune condition that speeds up the life cycle of skin cells, causing cells to build up rapidly on the surface of the scalp, leading to scaling, redness, and itchiness.
  • Eczema (atopic dermatitis): A condition that makes your skin red and itchy, and can affect the scalp, causing intense itching and discomfort.
  • Head lice: A common problem in children, caused by tiny, wingless insects that live on the human scalp, feeding on blood and causing intense itching.
  • Allergic contact dermatitis: A reaction to something that has come into contact with the scalp, such as hair dye, shampoo, or other hair products, leading to itching, redness, and sometimes blistering.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Tinea capitis (ringworm of the scalp): A fungal infection that can cause hair loss, itching, and redness on the scalp. If left untreated, it can lead to more serious complications.
  • Lupus: An autoimmune disease that can cause a range of symptoms, including an itchy scalp, hair loss, and skin rashes. Early diagnosis and treatment are crucial to prevent long-term damage.
• Rare diagnoses
  • Pityriasis amiantacea: A rare condition characterized by thick, yellow scales on the scalp, often accompanied by itching and redness.
  • Kerion: A rare and severe form of tinea capitis, causing intense inflammation, itching, and hair loss on the scalp.
  • Lichen planopilaris: A rare condition that causes inflammation and scarring on the scalp, leading to hair loss and itching.