Differential Diagnosis for Itchy Head in a Female After New Shampoo
- Single Most Likely Diagnosis
- Contact dermatitis: This is the most likely diagnosis due to the recent introduction of a new shampoo, which can cause an allergic reaction or irritation leading to itchiness.
- Other Likely Diagnoses
- Seborrheic dermatitis: This condition can be exacerbated by changes in hair care products, leading to itchiness and flakiness on the scalp.
- Dandruff: A common condition that can cause itchiness and flakiness, potentially worsened by the new shampoo.
- Psoriasis: Although less common, psoriasis can be triggered or worsened by certain hair care products, leading to itchy, scaly patches on the scalp.
- Do Not Miss Diagnoses
- Allergic contact dermatitis due to a specific ingredient (e.g., sulfates, parabens): While not the most likely, missing an allergic reaction to a specific ingredient could lead to prolonged discomfort and potentially more severe reactions if not addressed.
- Irritant contact dermatitis: Similar to allergic contact dermatitis, irritant contact dermatitis from the new shampoo could cause significant discomfort and needs to be considered to provide appropriate treatment.
- Rare Diagnoses
- Pityriasis simplex (simplex dandruff): A less common condition that could be considered if other diagnoses are ruled out.
- Tinea capitis (ringworm of the scalp): Although rare in adults, it's an important consideration, especially if the itchiness is accompanied by hair loss or other specific symptoms.
- Lichen simplex chronicus: A condition characterized by chronic scratching and rubbing of the scalp, leading to thickening of the skin, which could be a rare cause of itchiness in this context.