herpes zoster typically affects the thoracic and lumbar vertebra ( t3-l3 ) , and sacral herpes zoster is found in only 4% of cases . it usually occurs on one side of the sacrum , and in less than 1% of cases , it occurs on both sides . this dysfunction is experienced by only 4% of herpes zoster patients , but it can happen if the virus affects the sacral nerve . voiding dysfunctions caused by herpes zoster have also been reported in korea . however , the cases identified so far are limited to elderly people or patients with a deteriorated immune system , and no such occurrence has been found among young adults . against this background , we present the case of a 25-year - old man with a normal immune system who was hospitalized for scrub typhus and experienced herpes zoster on both sides of the sacral nerve . a 25-year - old man was hospitalized after seven continuous days of fever , chills , and a general feeling of weakness . his blood pressure was 140/70 mmhg , his pulse rate was 90 beats a minute , his respiratory rate was 20 breaths per minute , and his body temperature was 39.2. the patient reported feeling fatigued , pain upon urination , and pain in the anal area during urination and bowel movements . a skin rash was observed on the right side of the body , which was probably a eschar ( fig . 1 ) . the patient was a college student with no previous illness , and nothing of note was found in terms of family history , personal history , or travel history . the patient had climbed a mountain on september 20th , about two weeks before his hospitalization . the fever and chills started one week before hospitalization , and a dark red eschar of dead skin was found on the right side of the abdomen . because the diagnosis was scrub typhus , the patient was treated with doxycycline ( 100 mg orally 2 times a day for seven days ) . the fever began to subside three days after hospitalization . on the second day , the patient reported bloody stools and severe pain around the anus . the patient was examined by a surgeon to see if there was an anal laceration . a hip bath was advised , and anti - inflammatory medicine was administered . on the sixth day of hospitalization , the pain during urination lessened , but the patient still complained about voiding dysfunction . he had to suck in his stomach to urinate , and the amount of urine produced was less than usual . constipation started on the sixth day , and the anal sphincter was weaker than usual . on the eighth day , a skin rash , several blisters the size of rice grains , and calluses were observed on both sides of the anus ( fig . three days after the administration , the constipation improved , and from the fourth day the urinary dysfunction improved to the point of waiting a few seconds before urination and not needing to suck in the stomach anymore . the results of a blood test were as follows : white blood cell count , 4,930/mm ; hemoglobin , 14.1 g / dl ; platelet count , 179,000/mm ; aspartate aminotransferase , 56 iu / l ; alanine aminotransferase , 43 iu / l ; blood urea nitrogen , 17.35 mg / dl ; creatinine , 0.97 mg / dl ; albumin , 4.43 g / dl ; c - reactive protein , 7.9 mg / dl ; and erythrocyte sedimentation rate , 26 mm / hour . the immunofluorescence assay titer ( green cross labs , yongin , korea ) against orientia tsutsugamushi increased 4-fold or more . the fact that the blisters appeared bilaterally on each buttock simultaneously without any previous history , the size of the blister , intensity of pain , and the depth of the ulcer all indicated the diagnosis more likely as herpes zoster than herpes simplex . acyclovir ( 10 mg / kg every 8 hours ) was administered for seven days , and dexamethasone ( 10 mg / day ) was administered for six days and changed to prednisolone ( 100 mg orally ) . although urinary dysfunction due to herpes zoster is rare , it can happen if the virus affects related nerves , particularly s2 and s3 of the sacral nerve ; this affects the motor and sensory nerves of the bladder . chen , et al . reported that herpes zoster causes urinary dysfunction in only 4% of patients , but the ratio was 29% for patients who had the virus in the lumbosacral dermatome . regarding age and gender , herpes zoster accompanied by urinary dysfunction was mostly observed in middle - aged men , and the rate increased with age . richmond reported that 78% of herpes zoster patients who experienced urinary retention had the virus in the sacral nerve , 11% had the virus in the thoracolumbar nerve , and 11% had the virus in the upper sternal nerve . in cases where the virus affected the sacral nerve , many patients also experienced constipation or bowel incontinence . there are three types of urinary dysfunction caused by herpes zoster : cystitis , neuritis , and myelitis . vzv directly attacks the bladder wall to cause urinary dysfunction , and inflammation of the mucous membrane or blisters are observed upon cystoscopy . in neuritis , vzv lurks in a posterior ganglion and then affects the motor nerve of the sacral nerve . this disrupts the reflex of the detrusor muscle and weakens the bladder . in myelitis , the upper sacral nerve of the spinal cord is damaged , which causes a rigid bladder . voiding dysfunction caused by herpes zoster responds well to treatment and usually improves along with the disappearance of skin rashes . however , in some cases , acute urinary retention requires intermittent catheterization or an in - dwelling catheter . chen , et al . reported cases of catheter insertion or urethral catheterization for patients with urinary dysfunction caused by herpes zoster . the recovery took as little as two days to as long as eight weeks , but the average was 16 days . yamanashi , et al . reported an average recovery period of 5.4 weeks for seven patients , and park , et al . reported an average recovery period of 12 days for 20 patients . cases of urinary dysfunction caused by herpes zoster reported so far have included symptoms such as acute urinary retention , pain upon urination , urinary incontinence , cystitis , and neurogenic bladders . all the patients had either an impaired immune system or were elderly people aged 60 or older . there has been no reported case where a young adult with a normal immune system and without a previous illness had a dual infection of vzv and o. tsutsugamushi . there was a case of a 75-year - old female patient who had a hip replacement surgery , followed by a knee replacement surgery . she was affected by vzv in the sacral nerve , showing that in elderly people , multiple joint replacement surgeries can reactivate vzv . cases of the simultaneous outbreak of o. tsutsugamushi and rickettsia typhi , leptospira , or malaria have been reported in the past , but no case involving dual infection with herpes zoster has been recorded . one report discussed o. tsutsugamushi , a microorganism that causes monocyte - derived cells to trigger replication and activation of the cell , which in turn activates cd4 positive t lymphocyte . both vzv and o. tsutsugamushi cause infection within cells , but their interaction mechanisms have yet to be determined . this case study examined a patient who had voiding dysfunction and pain upon urination as the first symptoms of herpes zoster without dermatome lesions . his symptoms improved with the administration of acyclovir and steroids without catheter insertion , intermittent catheterization , or administration of an -blocker or anticholinergic drugs . in conclusion , when patients under treatment for acute infection report sudden urinary retention , the possibility of voiding dysfunction caused by herpes zoster needs to be considered . skin rashes on the bottom or lower limbs and changes in sensory nerves need to be checked . early administration of acyclovir or steroids might help to reduce the duration of urinary dysfunction .