Aquagenic pruritus

Aquagenic pruritus
Classification and external resources
Specialty	dermatology
ICD-10	L29.8 (ILDS L29.83)

Aquagenic pruritus is a skin condition characterized by the development of severe, intense, prickling-like epidermal itching without observable skin lesions and evoked by contact with water.^[1][2]

Presentation

Symptoms occur for up to 35 minutes; duration of an attack is typically between 10 and 120 minutes.^[3] However, sensitivity varies among sufferers, and since water is always present to some extent in the air (atmospheric humidity), those with greater sensitivity who live in moister regions are symptomatic almost constantly, while perspiration can cause frequent symptoms even in the driest climates.

Diagnosis

No definitive medical test is known for aquagenic pruritus. Rather, the diagnosis is made by excluding all other possible causes of the patient's itching. Since pruritus is a symptom of many serious diseases, it is important to rule out other causes before making a final diagnosis.

Etymology

The name is derived from Latin: aquagenic, meaning water-induced, and pruritus, meaning itch.

Pathogenesis

The exact mechanism of the condition is unknown, though some studies have suggested the itching occurs in response to increased fibrinolytic activity in the skin.^[4][5] Later studies indicated inappropriate activation of the sympathetic nervous system may play a part.^[6]

Treatment

Since the cause of the condition cannot be fully avoided in all cases, treatment is usually focused on topical itch management. This can be effected by the application of antipruritic lotions or creams, using phototherapy, or the application of hot or cold packs to the skin after water contact.^[4][7] Paradoxically, hot baths or showers help many patients, possibly because heat causes mast cells in the skin to release their supply of histamine and to remain depleted for up to 24 hours afterward.^[8] However, the itching associated with aquagenic pruritus is not clearly caused by histamine; other neurotransmitters, such as substance P, may be involved.

H1 and H2 blockers, such as loratadine, doxepin, or cimetidine, have historically been the first line of pharmacological treatment, but not all sufferers find relief with these medications. When antihistamines do work, loratadine seems to be the most effective for mild cases and doxepin most effective for more severe cases.

Naltrexone, hydrocortisone, or propranolol may relieve itching for some people.^[7][9][10]

See also

• Aquadynia
• Aquagenic urticaria
• List of cutaneous conditions
• List of allergies

References

Notes

1. Freedberg, Irwin M.; Eisen, Arthur Z.; Wolff, Klaus; Austen, K. Frank; Goldsmith, Lowell A.; Katz, Stephen I., eds. (2003). Fitzpatrick's Dermatology in General Medicine (6th ed.). McGraw-Hill. p. 401. ISBN 978-0-07-138066-9.
2. James, William Daniel; Berger, Timothy G.; Elston, Dirk M. (2005). Andrews' Diseases of the Skin: Clinical Dermatology (10th ed.). Saunders. p. 56. ISBN 978-0-7216-2921-6.
3. Steinman, Howard K.; Greaves, Malcolm W. (1985). "Aquagenic pruritus". Journal of the American Academy of Dermatology. 13 (1): 91–6. doi:10.1016/S0190-9622(85)70149-1. PMID 2411768.
4. Sekar, Cshanmuga; Jacob, Sheja; Srinivas, CR (2011). "Aquagenic pruritus: Beneath water 'lies'". Indian Journal of Dermatology. 56 (4): 446–7. doi:10.4103/0019-5154.84734. PMC 3179019. PMID 21965864.
5. Lotti, T.; Steinman, H. K.; Greaves, M. W.; Fabbri, P.; Brunetti, L.; Panconesi, E. (1986). "Increased Cutaneous Fibrinolytic Activity in Aquagenic Pruritus". International Journal of Dermatology. 25 (8): 508–10. doi:10.1111/j.1365-4362.1986.tb00863.x. PMID 3771051.
6. Nosbaum, Audrey; Pecquet, Catherine; Bayrou, Olivier; Amsler, Emmanuelle; Nicolas, Jean F.; Bérard, Frédéric; Francès, Camille (2011). "Treatment with propranolol of 6 patients with idiopathic aquagenic pruritus". The Journal of Allergy and Clinical Immunology. 128 (5): 1113. doi:10.1016/j.jaci.2011.05.001. PMID 21616525.
7. Holme, S. A.; Anstey, A. V. (2001). "Aquagenic pruritus responding to intermittent photochemotherapy". Clinical and Experimental Dermatology. 26 (1): 40–1. doi:10.1046/j.1365-2230.2001.00757.x. PMID 11260176.
8. People's Pharmacy. "Hot Water for Itches". Retrieved 25 July 2012.
9. Ingber, Sarah; Cohen, Paul D. (2006). "Successful Treatment of Refractory Aquagenic Pruritus with Naltrexone". Journal of Cutaneous Medicine and Surgery. 9 (5): 215–6. doi:10.1007/s10227-005-0144-x. PMID 16502200.
10. Nosbaum, Audrey; Pecquet, Catherine; Bayrou, Olivier; Amsler, Emmanuelle; Nicolas, Jean F.; Bérard, Frédéric; Francès, Camille (2011). "Treatment with propranolol of 6 patients with idiopathic aquagenic pruritus". The Journal of Allergy and Clinical Immunology. 128 (5): 1113. doi:10.1016/j.jaci.2011.05.001. PMID 21616525.

Further reading

• Steinman, Howard K.; Greaves, Malcolm W. (1985). "Aquagenic pruritus". Journal of the American Academy of Dermatology. 13 (1): 91–6. doi:10.1016/S0190-9622(85)70149-1. PMID 2411768.
• Office of Rare Diseases Research. "Aquagenic pruritus". National Institute of Health. Retrieved 18 April 2012.
• Salami, TA; Samuel, SO; Eze, KC; Irekpita, E; Oziegbe, E; Momoh, MO (2009). "Prevalence and characteristics of aquagenic pruritus in a young African population". BMC Dermatology. 9: 4. doi:10.1186/1471-5945-9-4. PMC 2673209. PMID 19374742.
• Santoso, Ivan; Santoso-Pham, Julia C. (September 1999). "Aquagenic Pruritus: Two Cases That Resolved with Histamine₁ and Histamine₂ Antagonists" (PDF). Hospital Physician: 67–8.
• "Aquagenic Pruritus". Family Practice Notebook. Retrieved 18 April 2012.
• Boodman, Sandra G. (May 16, 2011). "Common symptom, uncommon cause". Washington Post. Retrieved 3 Jul 2012.
• Sekine, R.; et al. (Mar 2012). "Anti pruritic effects of topical crotamiton, capsaicin, and a corticosteroid on pruritogen-induced scratching behavior.". 21 (3): 201–4.