Aquagenic pruritus is a condition in which contact with water of any temperature causes intense itching, without any visible skin changes. The symptoms may begin immediately after contact and can last for an hour or more. The cause of aquagenic pruritus is unknown; however, familial cases have been described. It may be a symptom of polycythemia vera or another underlying condition. Overall, treatment is a challenge. Antihistamines, UVB phototherapy, PUVA therapy and various medications have been tried with varying degrees of success.

• increased mast cell degranulation - release of granules rich in histamine and other compounds into the body by mast cells, a special type of cell that plays a role in the immune system
• increased circulating histamine
• release of acetylcholine - a chemical in the body which sends signals from nerves to muscles and between nerves in the brain
• increased skin fibrinolytic activity - activity that controls clot size by promoting the breakdown of clots

• Severe itching (may be the only symptom), prickling, stinging, or burning that consistently develops after skin contact with water, regardless of water temperature or salinity
• Lack of visible skin manifestations
• Reaction within minutes of exposure and lasting anywhere between 10 minutes to 2 hours
• Lack of another skin disease, underlying condition, or medication to account for the reaction
• Exclusion of all physical urticarias, symptomatic dermographism, and polycythemia vera, as well as other diseases that my have aquagenic pruritus as a symptom.

• Antihistamines
• Analgesics (pain relievers)
• Opioid receptor antagonists
• Alpha interferon 2b
• Cholestyramine
• Clonidine
• Topical capsaicin cream
• Naltrexone
• Adding sodium bicarbonate to bath water
• Selective serotonin reuptake inhibitors
• UV therapy - shown to be effective in about 50% of patients
• PUVA therapy
• Propranolol
• Atenolol
• Using baby oil or other hydrophobic emollients (skin softeners that repel water) before and/or after showering