Recent trends in patient characteristics and therapeutic choices for interstitial cystitis: Analysis of 282 Japanese patients


Takaaki Ito md, phd, Department of Urology, Tokyo Medical University Hachiouji Medical Center, 1163 Ttemachi Hachiouji, Tokyo 193-0944, Japan. Email:


Objectives:  We investigated the characteristics of recent male and female patients diagnosed with interstitial cystitis (IC), then investigated which therapy was chosen by the attending urologist.

Methods:  Materials were 282 IC patients diagnosed and treated during the past 3 years (sampling from Japanese IC database). Gender, age, medical history and predominant symptoms were investigated. In addition, we investigated the interval before a diagnosis was established. In laboratory findings, we investigated voided volume, urinalysis findings and cystoscopic findings. Regarding therapy, we investigated which therapy was chosen as the first line.

Results:  The gender ratio was about 1.0:5.6 (male : female). Regarding age distribution, patients in their 60s were the most frequent (65 cases, 31.3%). The interval before diagnosis of IC was 36.5 months on average (1–360 months). Regarding medical history, intrapelvic surgery was the most common and repeated urinary tract infection was next. The most frequent symptom was urinary frequency (295 cases, 98.3%). Urinary urgency was noted in 186 cases (62%) and supra-pubic pain was noted in 125 cases (41.6%). The once voided volume was 104.3 mL on average (50–200 mL). The most common cystoscopic finding was glomerulation (158 cases). Ulcer was present in only 19 cases. The most widely carried out therapy was hydrodistension (208 cases, 67.9%). Oral suplatast tosilate (197 cases, 65.6%), antihistamine (77 cases, 25.6%) and intravesical dimethylsulfoxide (69 cases, 23%) followed.

Conclusions:  Regarding characteristics, the age distribution was older than other countries. The most frequent symptom was urinary frequency. Oral suplatast tosilate was one of the popular therapies in Japan.


Interstitial cystitis (IC) was first reported by Hunner,1 who described a case of bladder ulcer and characteristic symptoms in 1914. The lesion became known as Hunner's ulcer. IC was considered a specific disease with specific findings, and the disease is rare in Asian countries. However, now, IC is generally considered a kind of syndrome showing urinary frequency, urgency and suprapubic pain.

We conducted a questionnaire survey of 300 hospitals in Japan in 1998 and reported that there were few IC patients; approximately two per 100 000 urological patients.2 Furthermore, there were 92 hospitals (30%) in which there were no IC patients within the previous year. In Europe in 1975, Ovarist reported the morbidity of IC in Finland using the criteria of medical history of chronic urinary dysfunction, urinary tract infection negative, edema, inflammatory cell invasion and fibrosis in bladder biopsy.3 According to that report, morbidity in Finland was 10.1:100 000 (population). Held conducted a questionnaire survey in 1987,4 and reported that there were at least 43 500 IC patients in the US. When cases similar to IC were included, there were potentially 217 500 patients. Jones et al. reported that there is a possibility that the incidence of IC in the total population is 0.5% based on the National Household Interview Survey.5 Based on these data, there seem to be marked differences between Japan and western countries, with regard to the morbidity of IC. It seems that the reasons for this are not only differences in race and lifestyle, but also a lack of knowledge and recognition of IC among both patients and medical staff.

The environment surrounding IC in Japan is rapidly changing. The society of interstitial cystitis of Japan (SICJ) was established in 2001, and a textbook about IC has been published for the first time in Japanese. In addition, a patient association was established. An international consultation of IC was carried out in Japan in 2003 by Ueda et al.6 Backed by rapid development, we surveyed recent trends in patient characteristics and therapeutic choices for IC and compare these findings with data from past reports.

Patients and methods

This study was based on 282 IC patients that the authors had diagnosed and treated recently. Based on medical records, we investigated gender, age, medical history such as allergy, autoimmune disease, history of pelvic surgery, and predominant symptoms (Table 1). In addition, we investigated the interval and number of medical institutions consulted before a diagnosis was established. In laboratory findings, we investigated the urine volume of once voided, urinalysis findings, and cystoscopic findings under anesthesia (endoscopic findings and quantity of infusion). Regarding treatment, we searched therapeutic strategies when patients visited the hospital for the first time.

Table 1.  The diagnostic criteria of interstitial cystitis
 1. Frequency (e.g. 10 times or more during the day)
 2. Urgency
 3. Reduced maximum single voided volume (e.g. 200 mL or less)
Diagnosed with:
 1. Glomerulation or Hunner's ulcer on cystoscopic examination, or
 2. Pain in the bladder


There were 43 males and 239 females, and the gender ratio was about 1.0:5.6. The age distribution is shown in Figure 1. Patients in their 60s were the most common (65 cases). The average patient age was 52.9 years. The interval before receiving a diagnosis of IC was 36.5 months on average with a range of 1–360 months. In addition, the number of medical institutions consulted ranged from one to 10, with an average of 1.8. In other words, patients generally had a checkup with about two medical institutions and needed approximately 3 years to obtain a diagnosis. It became clear from the medical history that a history of intrapelvic surgery was most frequent and repeated urinary tract infection followed (Fig. 2). Regarding allergic disease, pollinosis was the most common. Endometriosis and psychiatric disorder were noted in one case each. Regarding symptoms (Fig. 3), 238 patients reported that urinary frequency was the most common (216 cases, 90.7%), followed by urinary urgency (146 cases, 61.6%) and bladder pain (108 cases, 46%). Urethral pain was reported in three cases and pain on urination in two cases. The urine volume of once voided was 50–200 mL, and the average was 104.3 mL. Regarding urinalysis findings, pyuria was found in 19 of 234 cases (8.1%) and hematuria was found in 12 of 234 cases (5.1%). The quantity of water used for cystoscope under anesthesia was 100–1000 mL, and the average was 523.5 mL. Regarding cystoscopic findings, patch hemorrhage (so-called glomerulation) was found in all 110 cases in which findings were noted. Ulcer was found in 19 cases (12.1%) (Fig. 4). Interstitial cystitis symptom scores by Oleary and Sant7 were used in 113 cases. The average symptom score was 12.5 points (20 points maximum) and the problem score (20 points maximum) was 13.2 points. In 168 cases, the initial treatment was most frequently hydrodistension (108 cases). The order of other therapies excluding hydrodistension was 75 cases suplatast tosilate, 23 cases antihistamine, 35 cases dimethylsulfoxide (DMSO) bladder infusion (Fig. 5).

Figure 1.

Age distribution of interstitial cystitis patients.

Figure 2.

Past history of interstitial cystitis patients.

Figure 3.

Chief complaints of interstitial cystitis patients.

Figure 4.

Cystoscopic findings under anesthesia of interstitial cystitis patients.

Figure 5.

Therapies that were chosen as a first line for interstitial cystitis patients.


The gender ratio shows that females are more likely to experience IC than males (1.0:5.6). This is similar to the ratios the European and American reports. In addition, this ratio is almost the same as that shown in the results of the questionnaire survey2 (henceforth referred to as ‘the survey in 1998’) carried out by the author. Regarding patient age, those in the 50–60-year-old group were most common. This is also similar to the survey in 1998. However, it seemed that patient age tended to be slightly higher in Japan compared with that in Europe and America. We speculate that Japanese patients were older because patients went to urologists after symptoms worsened or an appropriate diagnosis was not obtained elsewhere. This is supported by the interval until diagnosis and the number of medical institutions consulted. It seems that this problem is associated with a lack of recognition and a sense of patient shame regarding urologic disease. Furthermore, recognition deficiency of urologists for IC is also severe and influences this issue. It has been continuously reported that IC is a rare disease in Japan. However, interstitial cystitis is not a specific disease based on Hunner's ulcer, but rather a syndrome involving urinary frequency, urgency and suprapubic pain. Actually, there are many patients who consult urologists with such complaints. We cannot draw a conclusion on the morbidity of this condition, because our investigation only examined cases from four institutions. However, a nationwide investigation is expected in the future.

The most frequent medical history for patients with IC involved intrapelvic surgery, followed by repeated urinary tract infection. However, in the survey in 1998, repeated urinary tract infection was most common and a history of intrapelvic surgery was less frequent. Many of the intrapelvic surgeries were gynecologic, suggesting that the causes of the urinary symptoms were also gynecologic, which may explain why IC was not included in the differential diagnosis. Although the cause is unknown, it cannot be denied that IC often occurs after intrapelvic surgery. This may indicate that pelvic surgery adversely affects vesical blood flow and nerves. The destruction of vesical glycosaminoglycan (GAG) by bacterial infection usually recovers with the end of a bacterial infection. However, it is thought that the destruction of GAG is persistent in IC. It is speculated that, because of the destruction of GAG and the loss of a non-specific defense mechanism, the bladder mucosa becomes susceptible to infection, which promotes the onset of IC. The European and American reports, as well as the survey in 1998, have suggested that a medical history of allergic disease such as pollinosis or asthma is related to this condition to some extent. Regarding a correlation with autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), the evidence is less clear.

The most common symptom was urinary frequency, which is the same as in the survey in 1998. However, there was as great an incidence of urinary urgency and less bladder pain compared with those in the survey in 1998. It is speculated that the incidence of bladder pain has not actually decreased, but rather untypical cases are being diagnosed more frequently, and physicians are now more aware of interstitial cystitis. Urinalysis findings were mostly normal, and the once voided volume decreased to around 100 mL. However, even if urinalysis findings show any abnormalities, a diagnosis of IC can not be excluded.

Around 500 mL of water on average could be injected into the bladder via cystoscope under anesthesia, indicating that a cystoscope under anesthesia is a better method of treating IC patients, and that it is impossible to carry out cystoscopic treatment without anesthesia. Bladder mucosal glomerulation was seen in half of cases. On the other hand, scar formation after ulcer healed, crack, and ulcer were seen in only around 10% of the cases. This means that many untypical cases could be diagnosed based on the symptoms. In addition, this proves that so-called conventional cases demonstrating Hunner's ulcer are in the minority.

Hydrodistension, which serves as both a diagnostic tool and therapy, was naturally the most commonly applied treatment. The major difference between our study and the survey in 1998 is that suplatast tosilate, which is an antiallergic agent is now available, whereas previously most cases received steroids. The efficacy of suplatast tosilate was reported for the first time by Ueda.8 The efficacy of steroids, however, was doubted early in both Europe and America, and is no longer widely used for the initial treatment because neither the appropriate dosage nor administration period has been established.


We reviewed recent trends in patient characteristics and therapeutic choices of 282 Japanese interstitial cystitis patients. It seemed that mild cases were being more frequently diagnosed as a result of symptoms, and/or cystoscopic findings. However, there were many senior patients, and it seemed that as a whole, recognition of interstitial cystitis is still insufficient in comparison with that in Europe and America. Bladder hydrodistension which serves as both a diagnostic tool and a treatment method is being carried out widely, and steroid use has been replaced by suplatast tosilate as a new therapy.