The Impact of Chronic Idiopathic Urticaria on Quality of Life in Korean Patients

Chronic idiopathic urticaria (CIU) is a chronic and often debilitating skin disease that can have a profound influence on patients' quality of life (QOL) and the ability to perform usual daily activities1. It is characterized by recurrent urticarial wheals of unknown cause that persist for more than 6 weeks2. CIU is a relatively common disease, and yet not much is known about the causative factors or its pathophysiologic mechanisms, which makes it difficult to cure. It predominantly affects adults, and remains a major problem in terms of etiology, investigation, and management. Due to its chronic nature, many patients suffer from significant detrimental effects on their QOL, and experience symptoms of depression or anxiety3. CIU can interfere with subjective well-being and daily life, yet evaluation of the disease has focused on clinical symptoms only. Treatment is often focused on skin symptoms rather than the effects these symptoms can have on the individual's QOL, which often leads to unsatisfactory management of the disease. To date, there have been no studies using QOL assessment in Korean patients with CIU.

The purpose of this study was to assess the impact of CIU on QOL in Korean patients, and to determine whether a relationship exists between QOL and the severity of disease. This would allow a better understanding of the disease, and provide for a more effective way to manage it.

Seventy four (45.4%) male patients and 89 (54.6%) female patients completed both questionnaires. There were 7 patients in the mild group (4.3%), 106 in the moderate group (65.0%), and 50 in the severe group (30.7%), with an average urticaria severity score of 8.5±1.9 (range 4~13). Mean age was 37.3±15.3 (range 9~80), and average duration of disease was 18.6±30.0 months. There were 102 patients in the idiopathic group (62.6%), 8 with concurrent cholinergic components (4.9%), 28 with concurrent pressure-induced components (17.2%), and 25 with both cholinergic and pressure-induced components (15.3%). QOL was divided into 6 categories and a 'QOL questionnaire' was used to assess the relationship between QOL and urticaria severity. The average QOL scores obtained from the questionnaire were as follows: SP (13.1±4.6), DLA (12.0±4.3), MS (10.3±3.3), SF (8.5±3.4), LA (6.1±3.0), and TIR (5.5±2.6). The results showed that the SP score was most affected and TIR the least. Spearman analysis of the six different categories showed a significantly positive correlation amongst them (p<0.05), meaning that an increase in QOL score in one category had a high probability of leading to an increase in all of the remaining five categories.

Analysis of the relationship between disease duration and QOL scores showed that, of the 6 QOL categories, only TIR correlated significantly with disease duration (p<0.05). In other words, the longer the disease lasted, the more treatment induced restrictions were placed upon the patients, while all other parameters did not differ according to the duration of disease.

Disease severity was found to have significant effects on SP, MS, SF, and LA (p<0.05); DLA and TIR were less influenced by disease severity. Of 163 patients, 61 (37.4%) were found to have concurrent physical components of urticaria, including pressure-induced or cholinergic urticaria. Interestingly, the presence of physical components was found to have a significant effect only on DLA and SF (p<0.05).

There have been numerous studies on the impact of CIU on QOL, some incorporating the use of assessment tools such as the World Health Organization QOL Assessment-Brief (WHOQOL-BREF)3, or the Dermatology Life Quality Index (DLQI)5-8. It is important to note that all studies done so far show that the overall impact of CIU on QOL is substantial. For example, QOL impairment in CIU patients was found to be similar to that in acne patients, and higher than that in patients suffering from vitiligo7. O'Donnell et al.1 studied 142 patients with CIU using an internationally validated QOL instrument and compared them to 98 patients with coronary artery disease. Upon evaluation, the scores for energy, social isolation and emotional reactions were similar in both groups, showing that the degree of QOL impairment in CIU is comparable to that of coronary artery disease.

Our results show that the longer the duration of disease, the more patients felt that treatment was restricting their lives. Long-term treatment can be increasingly frustrating with time because there is no defined duration. Also, disease severity had a significant effect on QOL categories associated with outward appearances or social activities, such as SP, MS, SF, and LA. Some patients in our study had concurrent physical components of urticaria, namely cholinergic or pressure-induced urticaria, or a combination of both. A study by Poon et al.7 showed that CIU subjects with concurrent pressure urticaria and cholinergic urticaria showed the greatest QOL impairment. Our study also evaluated the influence of concurrent physical components on QOL and found there was a significant and detrimental effect of the physical components on DLA and SF. However, because patients tend to avoid situations that are likely to induce symptoms, the effect on QOL of these components could have been underestimated. On the other hand, because this study was carried out in a university hospital setting, many of the patients had already been diagnosed with CIU, and had received treatment in a number of institutions, with discouraging results. Thus, many of the patients were likely to have more severe or more refractory cases of CIU, which suggests that the urticaria severity score and the QOL scores were overestimated.

Measurement of QOL is becoming increasingly important for evaluating the overall effectiveness of therapy and the impact of the symptoms of CIU on individuals. Grob et al.9 suggested that skin disorders can be characterized by a specific QOL profile, and profiles could be compared by dermatologists, helping them obtain a more objective view of QOL measurements. Because QOL questionnaires may be appropriate in one cultural setting but not valid in another, further studies are needed to assess international QOL tools in Korean CIU patients.

In conclusion, our results suggest that CIU has a significant negative impact on QOL of Korean CIU patients. It is therefore important to recognize these effects and utilize them in evaluating responses to treatment.