adrenal hyperplasia is a rare but life-threatening cause of frequency Excessive urinary excretion of sodium leads to marked dehydration with hyponatremia Female infants may exhibit virilization of the external genitalia Male infants may demonstrate increased pigmentation of the external genitalia and/or a relatively enlarged phallus Drugs and Toxins Drugs are a relatively common cause of frequency in adolescence Methylxanthines (caffeine, theophylline) and ethanol inhibit the production of antidiuretic hormone In addition to caffeinated drinks (soft drinks, coffee, black teas, energy drinks), chocolate is another source of caffeine Diuretic agents, such as furosemide or hydrochlorothiazide, can cause frequency when ingested other intentionally or accidentally Lithium and vitamin D are also associated with urinary frequency, interfering with renal responsiveness to antidiuretic hormone Many other medications may cause frequency, and a pharmacologic history should be obtained in the child who presents with urinary frequency Psychogenic Frequency may be a presenting symptom of water intoxication leading to polyuria Patients not have nocturia, as enuresis is related to excessive fluid intake The serum sodium and osmolality may be decreased Psychogenic polydipsia is an extremely unusual diagnosis in young children but may present in adolescence Water intoxication secondary to Munchausen syndrome by proxy, an unusual presentation of abuse in the younger child, is also a consideration The “extraordinary urinary frequency syndrome” can cause urinary frequency in pediatric patients Average age of onset is years (with a range of about to 11 years) Daytime frequency occurs as often as every minutes Nocturia is present in about half the cases but usually occurs only about one to two times per night Generally, only reassurance is needed, as this often resolves spontaneously within about months (although in some children, the duration of symptoms can be markedly longer) The etiology is unclear, but often has a psychogenic component, with an apparent “trigger” (school problems, parental death, sibling illness, etc.) identifiable in about half the cases After consultation, a trial of extended-release oxybutynin, behavior modification, and/or biofeedback techniques are therapeutic considerations EVALUATION AND DECISION The primary role of the emergency physician in evaluating the child with urinary frequency is to exclude significant underlying pathology that may result in