Bee or other insect stings are generally irritating or painful for a short period of time – even for people not allergic to the insect venom. This can make if difficult for a person to recognize a first time allergic reaction to an insect sting. Anyone concerned that they might be having an allergic reaction to an insect sting or bite should immediately contact a physician.

Someone else should drive the patient to the hospital if symptoms are severe (or the patient believes they are becoming severe). Otherwise, the patient should call 911 for an ambulance. Dizziness or fainting can occur in more severe reactions.

Symptoms of an allergic reaction to an insect sting often appear within 15 to 30 minutes. However, the reaction can also be delayed as much as four hours to a week later. Symptoms of a mild allergic reaction to an insect sting include:

• Mild nausea
• Cramps
• Hives
• Itching, tenderness
• Diarrhea
• Red, warm, swollen lump more than 2 inches in diameter at the sting or bite site

Those who experience noticeable symptoms that eventually pass should not be lulled into a false sense of security. They are at high risk for an even more serious reaction the next time they are stung. In the worst-case scenario, they could experience anaphylaxis, a potentially life-threatening condition that affects two or more body systems and requires immediate medical attention.

Though anaphylaxis does not occur on an individual’s first exposure to an allergen, it is important to note that people can experience anaphylaxis the very first time they react to an insect sting. Symptoms of anaphylaxis include:

• Intense itching over large areas of the body, including areas other than the sting site
  
  
• Feeling anxious
  
  
• Palpitations (an awareness of a strong, fast, irregular, abnormal or "galloping" heartbeat)
  
  
• Slurred speech
  
  
• Inability to swallow
  
  
• Swelling of the throat or tongue (angioedema)
  
  
• Hoarseness
  
  
• Rapid or weak pulse
  
  
• Red or swelling skin
  
  
• Hives (including on the lips, eyelids, throat and tongue)
  
  
• Stomach cramps
  
  
• Diarrhea
  
  
• Nausea or vomiting
  
  
• Wheezing
  
  
• Bluish tint to skin (cyanosis), including lips or nail beds
  
  
• Coughing
  
  
• Choking
  
  
• Nasal congestion
  
  
• Tightness in the chest
  
  
• Breathing difficulty

Most cases of anaphylaxis involve either cardiovascular or respiratory symptoms, or both. The pattern of symptoms also typically remains the same for an individual from episode to episode. Without immediate emergency treatment, anaphylaxis can quickly progress to life-threatening anaphylactic shock. More advanced symptoms include:

• Collapse or loss of consciousness
• Convulsions
• Loss of bladder control
• Shock
• Stroke
• Cardiac arrest
• Respiratory arrest

A delayed or large, local reaction to an insect sting is usually not a sign of anaphylaxis. Delayed swelling may indicate that the sting has become infected with bacteria. This type of reaction should always be examined by a physician to determine the cause.

Bites from some varieties of spider (which are arachnids, not insects) can lead to symptoms similar to a severe allergic reaction. Most spider bites are harmless. However, anyone who believes they may have been bitten by a poisonous spider should immediately contact a physician. Symptoms of such bites may vary depending on the type of spider, as follows:

• Black widow spider. Most who are bitten experience sharp pain and swelling at the bite site, which usually features two small fang marks. However, more serious symptoms can appear within 30 to 60 minutes and require immediate emergency medical attention. These include:
  
  
• • Muscle cramps and spasms at the bite site that increase and spread for 24 hours
  • Chills, fever, nausea and vomiting
  • Severe abdominal pain
  • Seizures
  • Stupor, restlessness and shock
  • Severe high blood pressure
    
    
• Brown recluse spider. Bites produce reddened skin and a blister at the bite site. Mild to intense pain and itching can follow for two to eight hours. An open sore with breakdown of the tissue (necrosis) also can develop within a few hours or days. This blackened tissue can take months to heal. Patients should seek medical care for necrosis, or any of the following symptoms:
  
  
• • Fever and chills
  • Skin rash over the body with tiny, flat purple and red spots
  • Nausea and vomiting
  • Joint pain
    
    
• Hobo spider. Symptoms include reddened skin that blisters within 36 hours. Numbness and tingling around the bite are common. About half of those bitten develop an open sore with breakdown of tissue (necrosis). Patients should see a physician if they develop necrosis or the following symptoms:
  
  
• • Headache
  • Weakness
  • Drowsiness
  • Vision problems
  • Hallucinations