Answer: You should report the more specific anaphylaxis diagnosis (995.0, Certain adverse effects not elsewhere classified; other anaphylactic shock) rather than the allergic reaction (995.3, Allergy, unspecified) or the symptoms (708.0, 786.07).
Although allergic reactions are a type of anaphylaxis, allergic responses involve local or general reaction to one body system, such as the skin. In contrast, anaphylactic shock affects multiple body systems, as your scenario describes. Generally, skin (urticaria) and respiratory (hoarseness, cough, wheezing) symptoms first appear, but cardiac (hypotension, arrhythmias) and gastrointestinal (vomiting, bloody diarrhea) problems may develop as well.
The term -shock- shouldn't dissuade you from thinking 995.0 is appropriate in this case. A diagnosis of anaphylaxis does not require the patient to be in shock. Instead the patient needs to show signs of an immediate response to specific antigen that results in life-threatening respiratory distress, according to the ICD-9 manual.
Use 995.0 as the secondary diagnosis and code the anaphylaxis cause--the bee sting--in the primary position. Because the venom triggers the reaction, you should assign 989.5 (Toxic effect of other substances, chiefly nonmedicinal as to source; venom) as dx 1 on the CMS-1500 claim form. Coding 995.3 without 989.5 would omit the reason for the shock.
Finally, you must identify the source of the anaphylactic syndrome. Although some payers do not accept external-cause codes, you should use an E code to explain what caused 995.0, according to ICD-9. The manual groups hornet, wasp and bee stings causing toxic reactions under E905.3 (Venomous animals and plants as the cause of poisoning and toxic reactions; hornets, wasps, and bees).
Don't separately code for the urticaria (708.0), wheezing (786.07) or allergic reaction (995.3). These diagnoses are inherent in 989.5, 995.0 and E905.3.