Index of Suspicion * Case 1: Pallor, Screaming, Sweating, and Breathing Difficulty Associated With Feeding in a 2-month-old Infant * Case 2: Swelling, Redness, Warmth, Tenderness, and Purulent Drainage Under the Nail in an Adolescent Girl * Case 3: Urticarial Rash, Fatigue, Achiness, and Dark Urine in an Adolescent Girl

Abstract

* ALT: : alanine aminotransferase AST: : aspartate aminotransferase BUN: : blood urea nitrogen CBC: : complete blood count CNS: : central nervous system CSF: : cerebrospinal fluid CT: : computed tomography ECG: : electrocardiography ED: : emergency department EEG: : electroencephalography ESR: : erythrocyte sedimentation rate GI: : gastrointestinal GU: : genitourinary Hct: : hematocrit Hgb: : hemoglobin MRI: : magnetic resonance imaging WBC: : white blood cell A 2-month-old term girl presents to an ED with a 3-week history of episodic difficulty in breathing together with screaming during and after feeding. The episodes are described as rapid breathing and shortness of breath that happen only with feeds and are associated with sweating and pallor, occurring multiple times a day. The patient has no other signs, including fever, runny nose, nasal congestion, drooling, noisy breathing, difficulty swallowing, or arching of the back with feeds. Her weight gain is appropriate for age. The patient has been evaluated for these complaints and felt to have colic or gastroesophageal reflux disease, for which ranitidine was prescribed. Her birth and perinatal histories are unremarkable. On physical examination, the following are found: temperature, 37.2°C; heart rate, 160 beats/min; respiratory rate, 52 breaths/min; pulse oximetry, 96% in room air; and blood pressure, 92/52 mm Hg. She is alert and has moderate respiratory distress with tachypnea and subcostal retractions. Her precordium is hyperdynamic. On auscultation, there is a gallop rhythm but no murmurs. Pulses are palpable but weak in four limbs, and capillary refill is prolonged at 4 seconds. There is no hepatomegaly. The findings on the rest of the examination are within normal limits. Laboratory findings include a normal CBC, capillary blood gas, and serum concentrations of lactic acid and electrolytes. Liver function tests, including serum albumin, prothrombin time, and partial thromboplastin time, also yield normal results. Cardiac enzymes are normal except for a mildly elevated serum troponin concentration at 0.43 ng/mL (normal 0 to 0.4 ng/mL). Additional evaluation leads to the diagnosis. A 15-year-old girl is hospitalized for progressive right thumb redness and swelling. She reports tactile fevers and chills. She has pain with movement of the thumb and tenderness over the affected area, but no limitation of motion or paresthesia. She was …