Reiter syndrome (& conjunctivitis, arthritis, balanitis, urethritis)

The finding of 3+ leukocytes on urinalysis suggests a diagnosis of urethritis for the sexually active adolescent boy described in the vignette. Urethritis usually is categorized as gonococcal or nongonococcal. Pathogens causing nongonococcal urethritis include Chlamydia trachomatis, Ureaplasma urealyticum, and Trichomonas vaginalis. Mycoplasma genitalium and herpes simplex virus (HSV) also have been associated with urethral infections, but lesions such as ulcers or blisters frequently accompany HSV infections. In approximately 20% of cases of urethritis, the organism is unknown.

Signs and symptoms of urethritis include dysuria, urinary frequency, and urethral discharge. Inflammation is confirmed by the presence of at least five polymorphonuclear leukocytes (PMNs) per high-power field on a Gram stain of a urethral smear or greater than 10 PMNs per high-power field in the centrifuged sediment of a first void urine. More specific tests may be undertaken to detect Neisseria gonorrhoeae and C trachomatis, although the presence of gram-negative intracellular diplococci in the urethral discharge supports the presumptive diagnosis of gonococcal urethritis. The absence of gram-negative intracellular diplococci with at least five PMNs per high-power field is indicative of nongonococcal urethritis. It is important to remember that in at least 50% of gonococcal infections, there is simultaneous infection with another sexually transmitted disease (STD) such as C trachomatis.

The teenage boy described in the vignette displays some of the physical findings typical of Reiter syndrome, which is characterized by conjunctivitis, arthritis, nonbacterial urethritis or cervicitis, and mucocutaneous lesions. The mucocutaneous lesions include balanitis; painless ulcerations on the tongue, palate, pharynx, and buccal mucosa; onycholysis; and skin vesicles or papules that can mimic psoriasis (keratoderma blennorrhagicum). Although the exact etiology is unknown, Reiter syndrome is believed to occur as a result of an autoimmune response to an STD, most commonly C trachomatis or an enteric bacterial infection. Individuals who have human leukocyte antigen (HLA) B-27 are at increased risk of developing Reiter syndrome.

Lymphadenitis, nephritis, pancreatitis, and pneumonitis are not present in patients who have Reiter syndrome, but may be associated with other arthritides. 

Lappa S, Moscicki AB. The pediatrician and the sexually active
adolescent: a primer for sexually transmitted diseases. Pediatr Clin
North Am. 1997;44:1405-1445
Neinstein LS. Reiter's syndrome. In: Adolescent Health Care: A
Practical Guide. 3rd ed. Baltimore, Md: Williams & Wilkins;