Aquagenic pruritus

A rare condition characterized by intense itching after contact with water

Aquagenic pruritus
Synonyms	Water-induced itching
Specialty	Dermatology
Symptoms	Severe itching triggered by contact with water, without visible skin changes
Complications	Sleep disturbances, anxiety, avoidance of bathing or swimming
Usual onset	Typically adolescence or early adulthood
Duration	Chronic or recurrent
Types	Primary (idiopathic), Secondary (associated with other conditions)
Causes	Unknown (primary); may be linked to polycythemia vera, Hodgkin lymphoma, or other systemic conditions (secondary)
Risk factors	Family history, underlying hematologic or systemic diseases
Diagnosis	Clinical evaluation, ruling out other pruritic disorders, assessment for underlying conditions
Differential diagnosis	Cholinergic urticaria, contact dermatitis, polycythemia vera
Prevention	Avoidance of hot water, use of non-irritating cleansers, antihistamines
Treatment	Antihistamines, phototherapy, beta blockers, capsaicin cream
Medication	Hydroxyzine, loratadine, propranolol, naltrexone
Prognosis	Good with symptom control; variable course depending on underlying cause
Frequency	Rare
Deaths	None directly attributed

Aquagenic pruritus is a rare dermatological condition characterized by intense itching triggered by contact with water, regardless of its temperature. This condition can significantly impact the quality of life of those affected, as it can occur after bathing, swimming, or even sweating.

Pathophysiology

The exact pathophysiology of aquagenic pruritus is not well understood. It is hypothesized that the condition may be related to the activation of mast cells in the skin, leading to the release of histamine and other inflammatory mediators. This release can cause the intense itching sensation experienced by patients. Some studies suggest a possible link to polycythemia vera, a type of blood disorder, although aquagenic pruritus can occur independently of any underlying systemic disease.

Symptoms

The primary symptom of aquagenic pruritus is severe itching that occurs after the skin comes into contact with water. The itching typically begins within minutes of exposure and can last for up to an hour. Unlike other forms of pruritus, aquagenic pruritus is not usually associated with visible skin changes such as rash or urticaria.

Diagnosis

Diagnosing aquagenic pruritus involves a thorough medical history and physical examination. It is important to rule out other causes of itching, such as allergic reactions, dermatitis, or systemic conditions like liver disease or kidney disease. In some cases, a water challenge test may be performed, where the skin is exposed to water to observe the reaction.

Management

Management of aquagenic pruritus can be challenging. Treatment options are primarily aimed at alleviating symptoms. These may include:

• Topical treatments such as emollients and antihistamines to soothe the skin.
• Systemic antihistamines to reduce itching.
• Phototherapy, which involves exposure to ultraviolet light to reduce symptoms.
• In some cases, medications such as beta-blockers or selective serotonin reuptake inhibitors (SSRIs) may be prescribed.

Prognosis

The prognosis for individuals with aquagenic pruritus varies. Some patients may experience a reduction in symptoms over time, while others may continue to have persistent itching. The condition is not life-threatening but can significantly affect daily activities and quality of life.

Related pages

• Pruritus
• Dermatology
• Mast cell
• Histamine
• Polycythemia vera