A Case of Concurrent Pyelonephritis and PID: Occam's Razor Versus Hickam's Dictum

ABSTRACT: In a sexually active girl with urinary symptoms, it is necessary to consider both diagnoses of urinary tract infection (UTI) and sexually transmitted infection (STI). Symptoms of both infections are nonspecific. Urinalysis results may be positive in either UTIs or STIs. Although a negative urine culture rules out UTI and pyelonephritis, a negative STI result does not rule out an STI. In our patient, a 16-year-old sexually active girl who thought she was pregnant, both pyelonephritis and pelvic inflammatory disease (PID) were diagnosed. Costovertebral angle tenderness coupled with a positive urine dipstick result indicated pyelonephritis, whereas purulent cervical discharge; a friable, reddened cervix; and cervical motion tenderness with adnexal tenderness signaled PID. Our patient’s symptoms resolved after treatment with 3 antibiotics: ciprofloxacin for pyelonephritis and ceftriaxone and doxycycline for PID.

Symptoms of urinary tract infection (UTI) are a common reason for office visits among adolescent girls and young women, especially those who are sexually active. Evaluation of urinary symptoms typically ends with the clinician providing an empiric antibiotic to cover common urinary pathogens. Although this often results in resolution of symptoms in adult women, in adolescent girls, a workup focused only on cystitis/UTI may miss the presence of a concomitant sexually transmitted infection (STI) and pelvic inflammatory disease (PID). The rates of infection with Chlamydia trachomatis and Neisseria gonorrhoeae are highest among sexually active girls aged 15 to 19 years and the rate of PID is also highest in this group.¹

In one study, of 142 sexually active adolescent girls and young women aged 14 to 22 years with urinary symptoms, 29 (20%) had UTI only, 42 (30%) had STI only, and 9 (6%) had both.² In the remaining 62 (44%) sexually active teenage girls and young women without a laboratory diagnosis of UTI or STI, an additional 14 were given diagnoses;  herpes simplex virus was diagnosed in 3, bacterial vaginosis (BV) in 5, candida in 2, and PID in 4. Dysuria was the most frequently reported urinary symptom, followed by urgency and frequency. The study supported the recommendation that sexually active adolescent girls with urinary symptoms be evaluated for both UTI and STI.²

PID often goes unrecognized because of the wide variation in symptoms and signs.^1,3 To follow the treatment recommendations for UTI or pyelonephritis alone would lead to inadequate treatment in the patient with concurrent diagnoses. The potential damage to the reproductive health of women when PID is left untreated should prompt clinicians to maintain a high suspicion and a low threshold for diagnosis of PID. When treating sexually active adolescent girls, it is important to consider the possibility of both infections simultaneously and provide treatment coverage for both sets of pathogens. In the following case report, we describe a patient with concurrent pyelonephritis and PID and the key features that helped establish the diagnoses. We also review the treatment options and prognosis for adolescent girls with  both of these infections.

RISK FACTORS FOR UTI,
STI, AND PID
In sexually active teens, UTIs and STIs share many of the same risk factors, including early sexual activity, number of sexual partners, unprotected intercourse, high coital frequency, and recent sexual intercourse.^4,5 A study by the CDC found that 65% of girls reported having had sexual intercourse by the twelfth grade, and only 46% of those who were sexually active used a condom the last time they had sex. In addition, girls who reported early sexual activity were more likely to have multiple sexual partners.⁶ By the twelfth grade, 14% of sexually active teenagers reported having had 4 or more partners.

UTI OR STI—OR BOTH?
Several articles have addressed the difficulty in differentiating UTIs from STIs.^2,4,7-9 Symptoms of both are nonspecific and may represent infection anywhere along the genitourinary tract. Urinalysis results that include the presence of leukocytes, nitrites, or blood may be positive in either UTIs or STIs. Although a negative urine culture rules out UTI and pyelonephritis, a negative STI result does not rule out an STI. As this case illustrates, it is possible for a patient to have concurrent UTI and STI.^2,4,8

Both pyelonephritis and PID are clinical diagnoses. Both of these infections are complications of milder infections, namely cystitis/UTI and cervicitis. The suprapubic tenderness and abnormal urine dipstick results are nonspecific findings that can be seen in both urinary and genital tract infections. Table 1 outlines the sensitivity and specificity of certain clinical features of urinary and genital infections in adolescent girls.

Recommended tests for sexually active adolescent girls who have urinary symptoms include urinalysis, urine culture, and urine nucleic acid amplification testing for gonorrhea and chlamydia.¹ A normal saline wet mount taken from the vagina and/or cervix can also be done to look for white blood cells, clue cells (BV), and trichomonads. Patients with urinary complaints cannot be accurately assessed through telephone triage and require an office visit.²

KEY FEATURES
Pyelonephritis. Pyelonephritis is an upper UTI of the renal pelvis and medulla; it begins with an untreated or unrecognized cystitis/UTI that ascends to the kidneys. Persons with pyelonephritis typically complain of flank pain, abdominal or pelvic pain, nausea, vomiting, and high fever. Examination reveals CVAT, which when coupled with abnormal urine dipstick results, points toward the diagnosis of pyelonephritis.

The organisms responsible for pyelonephritis occur at similar rates to those that cause cystitis/UTI. Escherichia coli is responsible for most UTIs in adolescents (as it is in other age groups); Staphylococcus saphrophyticus, Klebsiella, and Citrobacter are among other organisms reported.^2,4,9-11 UTIs and pyelonephritis are usually caused by one organism. A negative urine culture indicates that a bacterial cystitis/UTI or pyelonephritis is unlikely. Consequences of untreated pyelonephritis include renal abscesses, renal parenchymal injury, and sepsis.

PID. PID is an upper genital tract infection, which may start insidiously as an infection of the uterine cervix or cervicitis that ascends to the uterus, fallopian tubes, and ovaries. New-onset vaginal spotting and a friable, reddened cervix—as in the patient described—suggest the possibility of cervicitis.

The symptoms of PID range from subclinical to severe and make clinical diagnosis difficult.^1,3 Severe symptoms include lower abdominal pain and fever. Only 5% to10% of all cases are severe.³ The diagnosis of PID is probable when at least 1 of 3 criteria (CMT, uterine tendernesss, or adnexal tenderness) are present on pelvic examination and no cause for the illness other than PID can be identified.¹ Additional criteria, such as fever, abnormal cervical or vaginal mucopurulent discharge, numerous WBCs on saline microscopy of vaginal or cervical fluid, elevated sedimentation rate or C-reactive protein level, and laboratory documentation of cervical infection with N gonorrhoeae of C trachomatis, support a PID diagnosis. Results of endocervical screening tests for these organisms may be negative, and this does not rule out PID.

If the diagnosis of PID requires further confirmation, then endometrial biopsy, transvaginal and pelvic ultrasonography or MRI, or laparoscopy can be done. However, when PID is suspected, clinicians should initiate treatment immediately and not wait for test results.

PID sequelae are common and include chronic pain, infertility, tubo-ovarian abscess (TOA), ectopic pregnancy, and sepsis.^1,12 When an ovary is enlarged and a TOA is suspected (neither of which was present in the patient described), obtain a transvaginal and pelvic ultrasonogram.¹ Because the presentation of PID can be subtle and the consequences severe, clinicians should maintain a low threshold for diagnosis.

N gonorrhoeae and C trachomatis are the most common organisms that initiate PID.¹ It is estimated that up to 20% of untreated gonorrhea develops into PID.¹³ Other sexually transmitted pathogens as well as endogenous aerobic and anaerobic bacteria of the vaginal flora may be involved in PID.^1,14 BV also is present in many women who have PID¹; however, whether the incidence of PID can be reduced by identifying and treating women with BV is unclear.¹

TREATMENT AND OUTCOME
Both pyelonephritis and PID are usually treated on an outpatient basis unless the patient is severely ill.¹⁰

Pyelonephritis. Common outpatient treatments of cystitis/UTI and pyelonephritis are shown in Table 2. First-line treatment of pyelonephritis usually consists of ciprofloxacin, 500 mg orally twice daily for 7 to 14 days, or trimethoprim/sulfamethoxazole double strength, one tablet orally twice a day for 14 days.^4,10,11

PID. Common outpatient treatments of cervicitis and PID are listed in Table 3. Regardless of specific test results, PID is considered a polymicrobial infection and treatment must provide broad-spectrum coverage.^1,14 First-line outpatient treatment is usually ceftriaxone, 250 mg given intramuscularly once, and doxycycline, 100 mg taken orally twice daily for 14 days. Metronidazole is added to the oral PID treatment regimen for patients with BV or when there is a TOA.¹

Outcome of this case. Although sensitivity testing showed that the urinary tract pathogen C koseri was susceptible to ceftriaxone, the single intramuscular injection used to treat PID would have provided insufficient coverage of the pathogens associated with pyelonephritis. Subsequent sensitivity testing indicated that C koseri was susceptible to ciprofloxacin; however, this agent is not typically recommended for the treatment of PID, because of the increased patterns of quinolone resistance to N gonorrhoeae in the United States.¹ Although doxycycline is first-line treatment for PID, it is not typically chosen for UTIs.

Our patient was successfully treated with 3 antibiotics. Oral ciprofloxacin, 500 mg twice a day for 7 days, was prescribed to treat the pye-lonephritis. The PID was treated with a single 250-mg IM dose of ceftriaxone and oral doxycycline, 100 mg twice a day for 2 weeks. She was instructed to call the office if she could not tolerate her medications. At 1-week follow-up, the CVAT, CMT, and right-sided adnexal tenderness had resolved.

PROGNOSIS
Adolescent girls with pyelonephritis and PID are at risk for recurrent infections. Sexually active adolescent girls with previous UTI are at risk for subsequent cystitis/UTI⁵ and pyelonephritis. PID itself, because of fallopian tube damage, increases the risk of recurrent PID. Screening for HIV infection is recommended for all women who have PID. When results of cervical testing document chlamydial or gonococcal infections, the rate of reinfection within 6 months of treatment is high.¹ Repeated testing of all women who have been given a diagnosis of chlamydia or gonorrhea with or without PID is recommended 3 to 6 months after treatment regardless of whether their sex partners were treated.

OCCAM'S RAZOR VERSUS HICKAM'S DICTUM
When a clinician applies Occam’s razor in their practice, the goal is to identify a single diagnosis to account for all of the patient’s symptoms.¹⁵ This case supports the law of Hickam’s dictum, which states that “A man can have as many diseases as he damn well pleases.”¹⁶ A second diagnosis should not be excluded merely because the first has been assigned. The explanation for a constellation of findings may be that the patient has 2 or more common diseases simultaneously rather than a single rarer one. ■

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