A 42-year-old prison inmate is brought to the emergency department due to rapidly worsening shortness of breath. He was well at breakfast an hour ago. The patient has been seen in the emergency department several times over the last 2 years for asthma exacerbations, skin allergies, and alcohol intoxication. He is poorly adherent to maintenance asthma medications. Last night the patient took ibuprofen for shoulder pain that started after a physical altercation with another inmate. He is an active smoker with a 15-pack-year history. His last use of alcohol and cocaine was before he was incarcerated 2 months ago. Pulse is 118/min, respirations are 30/min, and oxygen saturation is 87% on 100% oxygen via nonrebreather mask. The patient is tall and thin, and he appears in severe respiratory distress with use of accessory muscles and subclavicular retractions. An urticarial rash is seen over the trunk and upper extremities. Which of the following is the most likely cause of this patient's breathing difficulty?

Question

A 42-year-old prison inmate is brought to the emergency department due to rapidly worsening shortness of breath.  He was well at breakfast an hour ago.  The patient has been seen in the emergency department several times over the last 2 years for asthma exacerbations, skin allergies, and alcohol intoxication.  He is poorly adherent to maintenance asthma medications.  Last night the patient took ibuprofen for shoulder pain that started after a physical altercation with another inmate.  He is an active smoker with a 15-pack-year history.  His last use of alcohol and cocaine was before he was incarcerated 2 months ago.  Pulse is 118/min, respirations are 30/min, and oxygen saturation is 87% on 100% oxygen via nonrebreather mask.  The patient is tall and thin, and he appears in severe respiratory distress with use of accessory muscles and subclavicular retractions.  An urticarial rash is seen over the trunk and upper extremities.  Which of the following is the most likely cause of this patient's breathing difficulty?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d1eb_f02a_bc81_a10951668163_MD0003_00 This patient with acute-onset respiratory distress, hemodynamic instability, and urticarial rash likely has anaphylaxis. The most common diagnostic criteria for anaphylaxis include: An acute illness involving the skin/mucosa and Either respiratory (eg, respiratory distress) or cardiovascular compromise (hypotension or signs of end-organ hypoperfusion). Other common manifestations include gastrointestinal, neurologic, and ocular symptoms. If the diagnosis is unclear, serum tryptase or plasma histamine may be helpful. The development of this patient's symptoms after breakfast suggests a possible food allergy (which can develop at any age). Risk factors for anaphylaxis include immune disorders such as asthma and mast cell disorders. Patients with underlying pulmonary or cardiovascular comorbidities are at increased risk for poor outcomes. Medications such as nonsteroidal anti-inflammatory drugs or beta-adrenergic blockers can exacerbate anaphylaxis by resulting in nonimmunologic mast cell activation or unopposed alpha-adrenergic effects, respectively. Treatment involves supportive care including airway management and medications such as intramuscular epinephrine, the preferred treatment. (Choices A and B) Anaphylaxis may be confused with an asthma exacerbation if skin involvement is minimal or missed by the clinician. Cardiac tamponade can also present with dyspnea and hemodynamic instability. Neither would explain the patient's diffuse urticarial rash. (Choice D) Myocardial infarction can present with a range of manifestations, including dyspnea and hemodynamic instability. However, in this patient, the lack of chest pain and the presence of an urticarial rash make myocardial infarction less likely. (Choices E and F) This patient's history of recent trauma places him at risk for a pulmonary contusion (PC) and tension pneumothorax (TP). PC typically presents with tachypnea, tachycardia, and hypoxia within 24 hours of blunt trauma and may result in acute respiratory distress syndrome (ARDS). TP is characterized by rapid-onset severe dyspnea, tachypnea, tachycardia, hypotension, and neck vein distension. PC, TP, and ARDS are not classically associated with skin involvement. Educational objective: Anaphylaxis is commonly characterized by an acute illness involving the skin/mucosa and either respiratory or cardiovascular compromise. Risk factors include immune disorders such as asthma. Medications such as nonsteroidal anti-inflammatory drugs can worsen anaphylaxis by resulting in nonimmunologic mast cell activation. References: Anaphylaxis: past, present and future. (http://www.ncbi.nlm.nih.gov/pubmed/20560905) Anaphylaxis - identification, management and prevention. (http://www.ncbi.nlm.nih.gov/pubmed/23529459)

A 42-Year-Old Prison Inmate Is Brought to the Emergency Department