A 12 year old male tells you he ate peanut butter by mistake. He has audible wheezes and his skin is pale. His pulse is weak and rapid. You should suspect:

• A. Extrinsic asthma
• B. Distributive shock
• C. Respiratory failure
• D. Obstructive shock

Answer: (B)

Recognizing anaphylaxis causing distributive shock.

After peanut exposure, the rapid onset of wheezing from bronchospasm along with pale, clammy skin and a weak, rapid pulse points to systemic vasodilation with poor perfusion—distributive shock from an anaphylactic reaction. In anaphylaxis, immune mediators release widespread vasodilation and increased vascular permeability, which drops blood pressure and reduces effective circulating volume, while also causing airway constriction. This combination explains both the breathing difficulty and the cardiovascular signs.

Extrinsic asthma can cause wheeze, but it isn’t typically accompanied by the systemic vasodilation and hypotension seen in anaphylaxis. Respiratory failure may develop if the situation worsens, but the immediate concern here is the distributive shock from an allergic reaction. Obstructive shock involves physical obstruction to circulation and isn’t driven by an allergic trigger in this scenario.