Prognosis

The prognosis is excellent for insect bite or sting patients who experience only local effects (pain, itching). Educating patients about things they can do to treat the exposure at home can help prevent unnecessary trips to the accident and emergency (A&E) department or doctor's surgery.

Severe reactions, such as anaphylaxis, have a good prognosis if recognised and treated expeditiously. Early use of adrenaline (epinephrine) prevents more severe reactions, biphasic reactions, repeat doses of adrenaline, and hospitalisation. Prompt airway and cardiovascular support will prevent most adverse outcomes from anaphylactic reactions. It is extremely important to educate victims of severe reactions that they are at high risk of another severe event. Education, provision of two adrenaline (epinephrine) auto-injectors and referral for possible desensitisation therapy are very important for these patients.[2][3]​​​[5][28]​​​[53]​​​[70]

The long-term prognosis for black widow bites is very good. Outcome from brown recluse envenomation is variable, with some risk of visible scarring or disfigurement.

All patients discharged from the A&E department after anaphylaxis should be warned of possible late-phase (delayed) anaphylactic reactions. Recommended durations of monitoring vary from a minimum of 2-24 hours in patients who have experienced anaphylaxis.[2][3]​​​​[28]​​[71][72]

Patients with mild to moderate reactions should be followed up by their primary doctor to monitor resolution of symptoms. Continued or worsening redness, pain, or fever several days after the sting or bite may indicate secondary infection. Spider bites and cellulitis are often clinically indistinguishable. In the absence of a witnessed bite, antibiotics are often started empirically. If antibiotics are used, coverage should be directed at common skin pathogens (Staphylococcus, Streptococcus) and community-acquired MRSA (according to local susceptibilities).

Patients with a severe allergic reaction should be evaluated by their primary doctor regarding referral to an allergist/immunologist for further testing.[39][70]​​[72][73][74]​​ It may involve skin testing, in vitro testing, and possibly desensitisation therapy. This is covered in detail in guidelines from AAAAI/ACAAI (American Academy of Allergy, Asthma & Immunology; American College of Allergy, Asthma & Immunology).[32][33]

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