What are the other Names for this Condition? (Also known as/Synonyms)

• Water-Induced Itching

What is Aquagenic Pruritus? (Definition/Background Information)

• Aquagenic Pruritus is an uncommon skin condition caused on contact with water. Water, at any temperature, may cause sudden and severe itching on skin, at the area of contact. However, no skin changes, marks, or lesions are generally visible
• The exact cause of development of Aquagenic Pruritus is unknown. Some cases are known to be inherited too. Experts feel that it may arise due to polycythemia vera or other underlying conditions such as the use of certain medications, emotional stress, and lactose intolerance
• Management of Aquagenic Pruritus is generally difficult, and there are no standard therapies. The use of antihistamines, betablockers, topical applications agents, and PUVA therapy have been considered by healthcare providers with varying success rates

Who gets Aquagenic Pruritus? (Age and Sex Distribution)

• Aquagenic Pruritus is a rare disorder. The presentation of symptoms may occur at any age
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Aquagenic Pruritus? (Predisposing Factors)

The risk factors for Aquagenic Pruritus may include:

• Living in humid/moist places
• Polycythemia vera: Aquagenic Pruritus may precede a diagnosis of polycythemia vera by several years or more
• Some types of benign and malignant conditions, such as, hypereosinophilic syndrome, juvenile Xanthogranuloma, myeloproliferative neoplasm, or myelodysplastic syndrome
• Lactose intolerance
• Certain infections such as hepatitis C
• Drug-induced Aquagenic Pruritus has been reported in patients treated with the following:
  • Clomipramine (a tricyclic antidepressant)
  • Bupropion (prescribed for smoking cessation)
  • Hydroxychloroquine and chloroquine (antimalarial drugs that may be used for rheumatoid arthritis and systemic lupus erythematosus too)
• Mental depression
• A family history of the condition may be a risk factor

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Aquagenic Pruritus? (Etiology)

The underlying cause of Aquagenic Pruritus is not well-established. In some cases, it has been observed as a feature of polycythemia vera, or arising from other conditions, such as a malignancy, infection, or adverse effect of medication use.

Researchers have proposed the following to explain the cause of Aquagenic Pruritus:

• Increased mast cell degranulation
• Increased circulating histamine
• Release of acetylcholine
• Increased skin fibrinolytic activity

Familial cases have been reported, especially when it is not observed in the setting of polycythemia vera or other conditions. This may suggest that the condition may develop from genetic factors too. However, the gene(s) that may be responsible for Aquagenic Pruritus is not yet identified.

What are the Signs and Symptoms of Aquagenic Pruritus?

The signs and symptoms of Aquagenic Pruritus may include:

• Intense itching (pruritus) in the water contact regions of the body
• Prickling, stinging, or burning sensation
• The legs are mostly affected; other body regions include the arms, trunk, abdomen, and hips
• Occasionally, the head and neck region (including the face) may be affected
• The palms and soles and mucosal surfaces are generally unaffected; thus, drinking or swallowing water does not cause any itching
• Visible skin manifestations, such as skin lesions, are not noted

Aquagenic Pruritus reaction of skin to contact with water occurs immediately within minutes of exposure and can last from anywhere between 10 minutes to 2 hours. The itching is not related to the temperature or salinity of water.

How is Aquagenic Pruritus Diagnosed?

It is generally difficult to diagnose Aquagenic Pruritus. The healthcare providers may arrive at a diagnosis following a process of excluding other probable conditions/disorders or medication use, and by observing the characteristic signs and symptoms. This may include:

• Physical (skin) examination of the individual and medical history evaluation; the absence of skin signs is generally noted
• Assessment of the presenting signs and symptoms
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Skin biopsy, if necessary: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Diagnostic tests to check for an underlying disorder or condition if present

A differential diagnosis may be necessary to eliminate other conditions that present similar signs and symptoms. This may include:

• Physical urticaria-including cold urticaria 
• Polycythemia vera
• Symptomatic dermographism

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Aquagenic Pruritus?

The complications of Aquagenic Pruritus may include:

• Emotional distress
• Constant anxiety
• Individuals may develop a phobia towards water
• Reduced quality of life in some cases

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Aquagenic Pruritus Treated?

There are no standard treatment measures available for Aquagenic Pruritus. The following have been considered by healthcare providers (some measures are more effective than the others):

• Antihistamine medications
• Pain-relief medications (analgesics)
• Opioid receptor antagonists and alpha interferon 2b
• Topical agents such as capsaicin cream
• Using bath water containing sodium bicarbonate
• Selective serotonin reuptake inhibitors (SSRIs)
• Ultraviolet therapy (reportedly effective in about 50% of the individuals) 
• PUVA therapy
• Beta blocker medication such as propranolol and atenolol
• Using baby oil or other hydrophobic emollients (skin softeners that repel water) before and/or after showering

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

How can Aquagenic Pruritus be Prevented?

• If the cause of Aquagenic Pruritus is known, seeking medical attention to address the cause can help prevent the condition
• Minimizing contact with water to the extent possible may be helpful

What is the Prognosis of Aquagenic Pruritus? (Outcomes/Resolutions)

• The prognosis of Aquagenic Pruritus is dependent upon the severity of the signs and symptoms and associated complications. However, the condition is not life-threatening
• Addressing the cause of Aquagenic Pruritus is known to help reduce the symptoms

Additional and Relevant Useful Information for Aquagenic Pruritus:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/