INTRODUCTION

Aquagenic pruritus (AP) is a dermatological condition characterized by unpleasant itching associated with contact with water, regardless of temperature, without visible skin lesions [1,2]. It manifests as an itching, tickling, or tingling sensation all over the body or localized parts such as the trunk or proximal parts of the limbs [3]. Several known properties of water may cause itching during bathing. These include the temperature of the water, its physico-chemical characteristics/ionic content and its pH, the soap used for the bath, the sponge, and the subsequent wiping, which may worsen symptoms in some patients. In addition, climatic conditions and temperature variations may affect the frequency and intensity of pruritus episodes [4].

AP is a rare condition in dermatological practice, and very few studies have been conducted on the topic. [2]. Studies conducted in Africa reported a hospital prevalence of 21% in Nigeria [4], 0.5% in Senegal [2], 0.6% in Côte d’Ivoire [4], and 21% in Mali [5]. In Togo, the prevalence was estimated to be 21.8% in 2020 among medical students [6].

Although BP has been recognized by practitioners, knowledge of its etiology, pathophysiology, and precise nature remains limited. However, several avenues may be considered by analyzing other types of pruritus. Thus, pruritus originates in the skin at the level of free nerve endings, and substance P, associated with other neuropeptides, is the main mediator [7]. A variation in their density, overexpression of receptors to neuropeptides or other pruritogenic mediators, and/or excessive release of these mediators could be the origin of BP [8].

In addition, the treatment of this condition is non-specific and highly unsatisfactory in the case of most patients, perhaps because the pathogenic and pathophysiological mechanisms leading to it are still poorly understood. Pharmacological studies have shown that aquagenic pruritus is associated with the local release of acetylcholine into the skin, mast cell degranulation, elevated blood histamine concentrations [9], and an increase in skin fibrinolytic activity before and after contact with water, which may explain the lack of skin lesions in this condition [10].

AP may lead to a highly distressing condition that most patients tend to ignore because of its relatively short duration; therefore, few resort to hospital practitioners. But, it nay also have a psychological effect, to the point of giving up bathing or developing a phobia of bathing [7] and may greatly alter the quality of life of the affected patient because taking a bath is a daily act of life [4]. In some families, AP appears to be hereditary [3]. It may be idiopathic or associated with various systemic diseases such as Hodgkin’s lymphoma, myelodysplastic syndrome, essential thrombocythemia, and polycythemia vera (Vasquez’s disease) [11,12].

Because the diagnosis of BP often goes unnoticed in the clinic and may be associated with other chronic diseases, impairing the quality of life of the patients, it is essential to document and describe the cases observed to promote a better understanding and treatment [13,14]. The objective of this study was to describe the characteristics of AP in patients who visited the Dermatology Department of Treichville University Hospital.

MATERIALS AND METHODS

RESULTS

A total of 81 patients between the ages of 5 and 70 years were diagnosed with PA during the study period. The median age of the patients was 30 years (25–35). The majority of the patients were female (64.2%), worked in the private sector (35.8%), or were students/pupils (29.6%). Regarding medical history, 24.0% of the patients had a history of asthma, and 76.0% had rhinitis (Table 1).

Table 1: Sociodemographic and clinical characteristics of the patients with aquagenic pruritus at the Dermatology Department of the Treichville University Hospital from January 1 to June 30, 2022.

Characteristics of Aquagenic Pruritus

BP was characterized by a tingling sensation (64.2%) and itching (56.8%). Most patients had generalized pruritus (75.3%) with high-intensity pruritus (71.6%). The triggering factors were dominated by contact with cold water (43.2 %), the use of superfatted soaps (65.4%), and perspiration (44.4%). The main calming factors reported were scratching (25.9%), topical application (14.8%), drying after bathing, and cold (13.6 %) (Table 2).

Table 2: Characteristics of aquagenic pruritus in the patients received at the Dermatology Department of the Treichville University Hospital from January 1 to June 30, 2022.

The median intensity of AP increased with the trigger, ranging from 6 for patients with pruritus after contact with cold water to 8 for those with pruritus after contact with cold and hot water followed by sweating (Fig. 1).

Figure 1: Intensity of pruritus by contact with the type of triggering factor.

Fig 2 shows that the high intensity of pruritus was more associated with contact with cold water and the use of fatted soaps. Most patients in contact with cold water experienced a strong itching and tingling sensation (Fig. 2a). Similarly, almost all patients using fatted soaps experienced tingling and itching sensations (Fig. 2b).

Figure 2: Sankey diagram showing the relationship between triggers and pruritus intensity. a) Relationship between water type, pruritus characteristics, and pruritus intensity. b) Relationship between soap type, characteristics, and pruritus intensity.

DISCUSSION

Aquagenic pruritus is a rare condition; nevertheless, it is highly relevant because of its association with various underlying diseases. Several disorders have been reported in association with PA, including hematological, lymphoproliferative, infectious, and neoplastic diseases [15].

More than half of the patients had generalized pruritus. Teclessou et al. observed generalized pruritus in 55% of cases in Togo [6]. In Poland, Lelonek et al. reported that 45.2% of the patients studied had localized pruritus [16].

This study observed that the patients had a high intensity of pruritus after contact with water, manifesting as intense tingling or severe itching that could persist for several minutes to several hours. The severity of pruritus may be influenced by prolonged exposure, repeated contact, and the general condition of the skin, especially if it is dry or irritating. This high intensity could impact the quality of life of patients, with consequences such as sleep disorders, anxiety, depression, and social isolation [14,17].

Contact with cold water and the use of superfatted soaps were associated with a high PA intensity. Cold is widely recognized as a cause of mast cell degranulation, whether in the skin or elsewhere, resulting in the release of histamine, a key mediator of pruritus [7]. In addition, the use of certain soaps, even superfatted ones, may influence the intensity of pruritus, especially if these products contain irritating or drying agents. This explains why practitioners recommend avoiding any irritating substances that could induce skin microlesions or promote an allergic reaction [4].

Various treatment modalities, including scratching and topical application, have been used to relieve pruritus. In contrast, in Nigeria, Salami et al. reported that patients with BP generated body heat by immediately wearing clothing after bathing, exertion, or applying occlusive creams for relief [7]. Heat is known to stabilize mast cells and prevent degranulation. In addition, the application of protective creams before exposure to water could be an interesting alternative option, as they protect the skin during washing or aquatic activities. The effects observed may range from the complete suppression of symptoms to a delay in the appearance of the papules [13,18].

Therefore, the management of itch in patients must include a holistic approach. The results of this study should raise awareness among practitioners confronted with patients complaining of itching, so that they may effectively diagnose and manage BP. Further research on the pathogenesis of AP could improve our understanding of this condition and optimize its management.

The main limitation of this study was its small sample size. This may be explained by the fact that patients are not always informed about the disease, particularly because there are no visible skin lesions. As a result, only some people consult for this pathology, which limits the number of diagnosed cases.

CONCLUSION

Aquagenic pruritus is an important dermatological condition, the pathological mechanisms of which are poorly understood. Diagnosis is primarily based on clinical characteristics, and appropriate management requires a comprehensive approach that includes the use of symptomatic treatments and the management of the triggering factors. Therefore, it is essential that practitioners are aware of this pathology to better diagnose and manage aquagenic pruritus in their patients.

REFERENCES

1.Steinman HK, Greaves MW. Aquagenic pruritus. J Am Acad Dermatol. 1985;13:91 6.

2.Diallo M, Abossolo BP, Niang S. Caractéristiques épidémiologiques, cliniques, histologiques et facteurs associés au prurit aquagénique idiopathique. Ann Dermatol Vénéréol. 2018;145(12, Supplement):S147.

3.Sekar CS, Srinivas CR, Jacob S. Aquagenic pruritus:Beneath water “LIES.”Indian J Dermatol. 2011;56:446 7.

4.Ecra EJ, Kourouma S, Allou AS, Kaloga M, Kouassi KouaméA, Kouassi Yao I. Aquagenic pruritus:Epidemiological and clinical features in Abidjan (Côte d’Ivoire). Nigerian J Dermatol. 2017;7:19-24.

5.Faye O, Cisse L, Berthe S, Dicko A, Thiam Ndiaye H, Traore P, et al. Prurit en consultation hospitalière àBamako, Mali. Int J Dermatol. 2012;51(s1):49 52.

6.Teclessou JN, Kombate K, Akakpo AS, Mouhari-Toure A, Zoua J, Kassang P, et al. Prevalence and clinical characteristics of aquagenic pruritus among medical and pharmacy students in Lomé(Togo). Dermatol Res Pract. 2020;2020:8420123.

7.Salami T, Samuel S, Eze K, Irekpita E, Oziegbe E, Momoh M. Prevalence and characteristics of aquagenic pruritus in a young African population. BMC Dermatol. 2009;9:4.

8.Potasman I, Heinrich I, Bassan HM. Aquagenic pruritus:Prevalence and clinical characteristics. Isr J Med Sci. 1990;26:499 503.

9.Greaves MW, Black AK, Eady RA, Coutts A. Aquagenic pruritus. BMJ. 1981;282:2008 10.

10.Lotti T, Steinman HK, Greaves MW, Fabbri P, Brunetti L, Panconesi E. Increased cutaneous fibrinolytic activity in aquagenic pruritus. Int J Dermatology. 1986;25:508 10.

11.Le Gall?Ianotto C, Brenaut E, Gouillou M, Lacut K, Nowak E, Tempescul A, et al. Clinical characteristics of aquagenic pruritus in patients with myeloproliferative neoplasms. Br J Dermatol. 2017;176:255 8.

12.Cao T, Yong AA, Tan KB, Tey HL. Idiopathic aquagenic pruritus:Pathogenesis and effective treatment with atenolol. Dermatol Ther. 2015;28:118 21.

13.Wang F, Zhao YK, Luo ZY, Gao Q, Wu W, Sarkar R, et al. Aquagenic cutaneous disorders. JDDG:Dtsch Dermatol Ges. 2017;15:602 8.

14.Siegel FP, Tauscher J, Petrides PE. Aquagenic pruritus in polycythemia vera:Characteristics and influence on quality of life in 441 patients. Am J Hematol. 2013;88:665 9.

15.Heitkemper T, Hofmann T, Phan NQ, Ständer S. Aquagenic pruritus:Associated diseases and clinical pruritus characteristics. J Dtsch Dermatol Ges. 2010;8:797 804.

16.Lelonek E, Matusiak Ł, Wróbel T, Kwiatkowski J, Szepietowski JC. Burden of aquagenic pruritus in polycythaemia vera. Acta Derm Venereol. 2018;98:185 90.

17.Reich A, Hrehorów E, Szepietowski JC. Pruritus is an important factor negatively influencing the well-being of psoriatic patients. Acta Derm Venereol. 2010;90:257 63.

18.Baptist AP, Baldwin JL. Aquagenic urticaria with extracutaneous manifestations. Allergy Asthma Proc. 2005;26:217 20.