The Characteristics of Pruritus in Thai Type2 Diabetic Patients and its Impact on their Dermatology Life Quality Index

Dermatological manifestations in diabetes mellitus include those due to disease itself, as well as complications and their respective treatments...

and diabetic dermopathy, while short-term effects cause troublesome symptoms such as fatigue, abnormal weight change, and insomnia. These symptoms are known to adversely affect patients' quality of life and mental health [1][2][3]. Dermatological manifestations in diabetes mellitus are due to disease itself, complications and their treatments. Dermatologic lesions associated with diabetes mellitus are classified into disease specific and non-specific symptoms. Consequences of neurovascular complications such as macroangiopathy, microangiopathy, and diabetic neuropathy are also formed [4][5][6].
Diabetic treatments can cause various dermatologic lesions.
Treatment with insulin can cause allergic reactions, lipoatrophy, and insulin edema [5,6]. It has also been found that some conditions are associated with diabetics than nondiabetics such as lichen planus, eruptive xanthomas, perforating dermatosis, vitiligo, and yellow nails [5,6]. Pruritus, or itching, involves cutaneous manifestations over extended periods and often causes patients psychological distress, and causes which leads to skin infection [7,8]. Common causes of pruritus in dermatological conditions are atopic dermatitis, urticaria, psoriasis, and insect bite. However, systemic medical conditions include chronic renal failure, jaundice, chronic hepatitis, diabetes mellitus, and thyrotoxicosis [9][10][11][12].
To our knowledge, there are some studies about the association between plasma glucose level and pruritus. They found that higher plasma glucose levels are significantly associated with a greater prevalence of pruritus in T2DM patients [9].
T2DM is associated with quality of life in many areas such as family, daily life, and self-esteem [13]. Histamine level is associated with pruritus; hence, antihistamines are considered to play a role in the reduction of itching. However, there is no standard treatment guideline for regularly using antihistamine in T2DM patients [14][15][16]. Nevertheless, the data for an association between pruritus and health-related quality of life in Thai T2 DM patients are still lacking. Therefore, the purpose of our study was to evaluate the dermatology quality of life among Thai T2DM patients with pruritus and the association between plasma glucose level and degree of itching using Dermatology Life Quality Index (DLQI) questionnaires and the Itching Numeric Rating Scale (NRS) [17,18]. The factors considered included age, gender, educational degree, and duration of type 2 DM [1].

Materials and Methods
This study was approved by Vajira Hospital Institutional Review Board. The study design was a prospective descriptive study. Thai

Statistical Analysis
All analyses were performed by using SPSS software version 22.0. Continuous data were described as mean and standard deviation. The statistical comparisons of the DLQI results between subpopulations were performed by using Fisher's exact test and Mann-Whitney U Test. A p-value < 0.05 was considered statistically significant. Correlation analysis was made by using Spearman's Correlation Test [19][20][21].

Results
Of the 300 patients enrolled, 177 patients were female, and the rest were male. Table 1 shows demographic data in patients studied. Almost half of them were unemployed. More than fifty percent of them were married and living with their spouse. One hundred and fifty-nine patients graduated from primary school. The average duration for having DM was nine years, and the average plasma glucose level was 160 mg/dL while average HbA1C level is 7.9%. Table 2 shows the characteristics of pruritus in our patients studied.
We found no specific area of pruritus and most of the people have pruritus in more than one area. Approximately forty percent of the patients mentioned that head, neck, body, and lower extremities are the most itch areas, while upper extremities are less affected.
After univariate and multivariate analysis, our study found that serum HbA1C level above 6.5%, no usage of topical steroids and topical moisturizer were significantly associated with pruritus, while anti-histamine usage, serum fasting plasma glucose >126 mg/dL, and having diabetes for over 10 years were not relevant factors in pruritus (Data shown in Table 3).  Data are presented as n (%)  Table 4 shows the numeric rating scale in each range and average score. Our study shows VAS mean score were3.15±1.93. of our subjects had a mild to moderate degree of pruritus. Table 5 shows associated factors that affect pruritus. We found that dry skin, sweating, and cold weather were statistically aggravating factors (when using univariate analysis; p-value < 0.05). However, cold weather is not statistically significant after multivariable analysis. Table 6 shows DLQI score in our patients studied. Our study found that the mean DLQI score is 1.98. More than half of our subject responded that their quality of life was not affected by pruritus [22].

Discussion
Type-2 diabetes mellitus (T2DM) is a systematic disease, in which multiple organs are involved including the dermatological system. The effects of T2DM to dermatological problems come from the disease, complications, and the consequences of treatment [1][2][3]. Pruritus (itching) is one of the most common clinical symptoms. It often presents in T2DM patients with adverse effects on their quality of life and mental status [7]. Of all the systemic diseases associated with pruritus, renal failure is probably the most common underlying disease. In diabetes mellitus, generalized pruritus is rare but localized pruritus is more frequent, especially in the perianal/ genital region, and caused by fungal infection [23]. To date, there have been many studies about the association between plasma glucose level and pruritus [9,13]. They found that an elevated plasma glucose level is significantly associated with a greater prevalence of pruritus in T2DM patients [9,13]. Nevertheless, data for the association between pruritus and health-related quality of life in Asian T2DM patients are still lacking.
Our study showed that eighty percent of T2DM patients had mild to moderate pruritus (NRS 0.0 -6.9). We found that most of them had clinical pruritus more to than one part of the body. The most affected areas were the face, torso, and lower extremities,

Conclusion
Our study found that the control of HbA1C level, usage of topical steroids and moisturizers are statistically associated with clinical pruritus. Dry skin and sweating were statistically aggravating factors. Although our study found that pruritus had small effects on quality of life, we also found that use of topical steroids and moisturizers is significantly helps improve clinical pruritus. Thus, giving moisturizer to T2DM patients may help to improve and prevent their pruritus symptoms.