Differential Diagnosis
- Single most likely diagnosis
- Aquagenic pruritus: This condition is characterized by intense itching that worsens with contact with water, without any visible skin lesions. The symptoms match the description provided, making it the most likely diagnosis.
- Other Likely diagnoses
- Atopic dermatitis: Although the skin examination is normal, atopic dermatitis can have a variable presentation, and some patients may experience worsening symptoms with water contact due to the disruption of the skin barrier.
- Irritant contact dermatitis: This condition can cause itching and discomfort, which may worsen with water exposure, especially if the water is hot or contains irritants.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Erythromelalgia: A rare disorder that causes burning pain, heat, and redness in the hands and feet, which can be exacerbated by water exposure. Although unlikely, it's crucial to consider due to its potential severity.
- Cholinergic urticaria: A type of physical urticaria that can cause itching, hives, and other symptoms in response to water exposure, which can be life-threatening if associated with anaphylaxis.
- Rare diagnoses
- Polycythemia vera: A rare blood disorder that can cause itching, especially after water exposure, due to the release of histamine from mast cells.
- Mastocytosis: A condition characterized by an accumulation of mast cells in the skin, which can cause itching, flushing, and other symptoms, including worsening with water exposure.