Case Discussion
Posted: 07 Jan 2012, 22:58
A 68-year-old woman presents to the emergency department (ED) complaining of progressive shortness of breath, flank pain, fever, and weakness. A diffuse, pinkish rash that had started 6 hours before presentation is noted over her extremities and trunk. She has a history of diabetes and has been taking glyburide irregularly, with poor glycemic control documented by blood glucometer record. About 10 days ago she noted a small ulcer on the dorsum of her left foot that started to grow in size, with associated low-grade fevers and pain along her left leg. Her primary doctor prescribed her a course of amoxicillin, which she is currently taking. She takes no other medications, does not smoke tobacco, and does not use illicit drugs or alcohol. She reports no headache, neck stiffness, nausea, vomiting, expectoration, chest pain, cough, sore throat, abdominal pain, changes in urine color, melena, hematemesis, or bleeding. She has no medical allergies and has not recently traveled outside her home country of Cuba.
On physical examination, the patient is a mildly obese female who appears very ill and is in acute distress. Pallor, mild cyanosis, poor capillary refill (3-4 sec), and a weak, rapid radial pulse are noted. She is conscious and is alert and oriented. She has a patent airway and her respiratory rate is 30 breaths/min with bilateral rales and diminished air entry into both lung bases. Normal S1 and S2 heart sounds are heard with no discernible murmur. She is tachycardic with a heart rate of 122 beats/min. The pharyngeal examination shows no erythema or exudate. The axillary temperature is 98.6°F (37°C). Her blood pressure is 85/50 mm Hg. No jugular venous distension is noted. The abdominal examination is unremarkable; examination of the stool is negative for occult blood. Her skin appears plethoric and cool with a diffuse, nonvesicular, nonpalpable, petechial, non-blanching rash (see Figures 1-3). A necrotic, crusted black eschar is observed on her left leg. The eschar is about 5 cm in diameter. Neurologic examination is unremarkable and there are no signs of meningismus.
Laboratory studies are ordered; these include a complete blood cell count with a hemoglobin of 14.4 g/dL (144 g/L); a hematocrit of 42% (0.42 L/L); white cell count of 7 x 103 /µL (7 x 109 /L) with a neutrophilic predominance of 79%; a platelet count of 250 × 103/µL (250 × 109/L); and a normal peripheral smear. Her coagulation studies at admission are all normal, but her creatinine is significantly elevated at 3.2 mg/dL (285 µmol/L). Arterial blood gas analysis (with supplemental oxygen) reveals a pH of 7.10, PaO2 of 80 mm Hg, PaCO2 of 49 mm Hg, SaO2 of 90%, bicarbonate of 13 mmol/L, and a base deficit of -15.2 mmol/L. A lumbar puncture is performed, which shows a clear acellular cerebrospinal fluid with low glucose 34.8 mg/dL (1.9 mmol/L) and a normal protein level. The results of a urinalysis are normal. She is hypoglycemic, with finger stick glucose of 58.7 mg/dL (3.2 mmol/L). Electrolyte analysis demonstrates mild hyperkalemia (5.7 mmol/L). A chest radiograph shows changes consistent with early adult respiratory distress syndrome (ARDS). The patient is resuscitated in the ED with intravenous (IV) crystalloid, IV steroids, vasopressor support, and IV antibiotics. Endotracheal intubation is performed due to worsening hypoxic respiratory failure, and the patient is placed on a mechanical ventilator; the patient is then transported to the intensive care unit. Gram stain and blood culture samples of the skin lesions are obtained
WHAT IS THE DIAGNOSIS ?
Henoch-Schönlein purpura
Anaphylactic shock secondary to amoxicillin
Waterhouse-Friderichsen syndrome
Toxic epidermal necrolysis
On physical examination, the patient is a mildly obese female who appears very ill and is in acute distress. Pallor, mild cyanosis, poor capillary refill (3-4 sec), and a weak, rapid radial pulse are noted. She is conscious and is alert and oriented. She has a patent airway and her respiratory rate is 30 breaths/min with bilateral rales and diminished air entry into both lung bases. Normal S1 and S2 heart sounds are heard with no discernible murmur. She is tachycardic with a heart rate of 122 beats/min. The pharyngeal examination shows no erythema or exudate. The axillary temperature is 98.6°F (37°C). Her blood pressure is 85/50 mm Hg. No jugular venous distension is noted. The abdominal examination is unremarkable; examination of the stool is negative for occult blood. Her skin appears plethoric and cool with a diffuse, nonvesicular, nonpalpable, petechial, non-blanching rash (see Figures 1-3). A necrotic, crusted black eschar is observed on her left leg. The eschar is about 5 cm in diameter. Neurologic examination is unremarkable and there are no signs of meningismus.
Laboratory studies are ordered; these include a complete blood cell count with a hemoglobin of 14.4 g/dL (144 g/L); a hematocrit of 42% (0.42 L/L); white cell count of 7 x 103 /µL (7 x 109 /L) with a neutrophilic predominance of 79%; a platelet count of 250 × 103/µL (250 × 109/L); and a normal peripheral smear. Her coagulation studies at admission are all normal, but her creatinine is significantly elevated at 3.2 mg/dL (285 µmol/L). Arterial blood gas analysis (with supplemental oxygen) reveals a pH of 7.10, PaO2 of 80 mm Hg, PaCO2 of 49 mm Hg, SaO2 of 90%, bicarbonate of 13 mmol/L, and a base deficit of -15.2 mmol/L. A lumbar puncture is performed, which shows a clear acellular cerebrospinal fluid with low glucose 34.8 mg/dL (1.9 mmol/L) and a normal protein level. The results of a urinalysis are normal. She is hypoglycemic, with finger stick glucose of 58.7 mg/dL (3.2 mmol/L). Electrolyte analysis demonstrates mild hyperkalemia (5.7 mmol/L). A chest radiograph shows changes consistent with early adult respiratory distress syndrome (ARDS). The patient is resuscitated in the ED with intravenous (IV) crystalloid, IV steroids, vasopressor support, and IV antibiotics. Endotracheal intubation is performed due to worsening hypoxic respiratory failure, and the patient is placed on a mechanical ventilator; the patient is then transported to the intensive care unit. Gram stain and blood culture samples of the skin lesions are obtained
WHAT IS THE DIAGNOSIS ?
Henoch-Schönlein purpura
Anaphylactic shock secondary to amoxicillin
Waterhouse-Friderichsen syndrome
Toxic epidermal necrolysis