Allergy intradermal testing

Overview

Allergy intradermal testing is a skin test used to find out what substances you may be allergic to. A tiny amount of a suspected allergen (like pollen, pet dander, or insect venom) is injected just under the top layer of your skin. If you are allergic, a small red bump (like a mosquito bite) appears within about 15–20 minutes.

Yes, it is a common and trusted way to diagnose allergies, especially when skin prick tests are unclear or when confirming certain allergies.

It is used for people of all ages who might have allergies – from children to older adults. It is especially common for people with suspected insect venom allergies or drug allergies.

Symptoms

Common symptoms

• Sneezing, runny or stuffy nose
• Itchy eyes, nose, or skin
• Hives (raised, itchy welts on the skin)
• Wheezing or shortness of breath (in some cases)

Symptoms in children

• Children may have the same symptoms as adults, like runny nose or itchy skin.
• They may also get upset or fussy due to the discomfort of allergy symptoms.

Symptoms in older adults

• Older adults may experience the same symptoms, but skin may react more slowly.
• They may be more likely to have other health conditions that complicate symptoms.

Causes

Main causes

• Allergies themselves are caused by your immune system overreacting to a harmless substance, like pollen, food, or insect venom.
• The intradermal test is used to identify which specific substance is triggering your allergy.

Risk factors

• Family history of allergies
• Having other allergic conditions like asthma or eczema
• Previous allergic reactions to medicines such as penicillin

When to see a doctor

See a doctor urgently if:

• If you have a severe allergic reaction (anaphylaxis) – call your local emergency number immediately.
• If you have sudden, severe hives or trouble breathing after a potential allergen exposure.

Book a routine appointment if:

• If you have regular allergy symptoms that bother you and you want to find out the cause.

Diagnosis

Allergies are diagnosed through a combination of your medical history, symptom diary, and skin testing like the intradermal test. Your doctor will ask about when and where you get symptoms.

Tests that may be done

• Skin prick test (a drop of allergen is placed on the skin and pricked with a tiny lancet)
• Intradermal test (a tiny amount of allergen is injected under the skin)
• Blood tests (look for antibodies called IgE that are linked to allergies)

What to expect at your appointment

For the intradermal test, you will go to a clinic where a nurse or doctor cleans a small area of your arm or back. They inject a tiny amount of each suspected allergen just under your skin. This feels like a quick pinch. Then you wait about 15–20 minutes. If you are allergic to any substance, a raised, red bump (like a mosquito bite) will appear. The doctor will measure it and discuss the results with you.

Treatment

If the intradermal test finds you are allergic to something, your doctor will work with you to create a plan. Treatment focuses on avoiding the allergen, managing symptoms with medications, and sometimes building up tolerance (immunotherapy).

Self-care at home

• Avoid known allergens as much as possible (keep windows closed during high pollen, use dust-mite covers, etc.)
• Keep a symptom diary to track what triggers your reactions
• Carry an emergency plan if you are at risk of severe reactions – your doctor can advise what to carry

Medical treatments

Your doctor may recommend medications such as antihistamines (which block the allergic reaction) or corticosteroid nasal sprays to reduce inflammation. For some allergies, especially insect venom or severe environmental allergies, immunotherapy (allergy shots or under-the-tongue tablets) can help your immune system become less sensitive over time. Always take medications exactly as your doctor prescribes.

When is surgery considered?

Surgery is not a treatment for allergies. However, if you have chronic sinusitis or nasal polyps related to allergies, your doctor might discuss procedures like nasal endoscopy or surgery to improve breathing.

Living with this condition

After an intradermal test, you will know what you are allergic to. This makes it easier to avoid triggers and manage your symptoms. Check labels, ask about ingredients when eating out, and keep your home as allergen-free as possible.

Lifestyle tips

• Vacuum and dust regularly to reduce indoor allergens
• Wash bedding in hot water weekly to kill dust mites
• Use a high-quality air filter if needed
• Wear a medical alert bracelet if you have a serious allergy (like to insect venom)

Diet and exercise

If you have food allergies, read food labels carefully and tell restaurant staff. Exercise is good for overall health, but if exercise triggers symptoms (like exercise-induced anaphylaxis), talk to your doctor about how to stay safe.

Mental health and emotional wellbeing

Living with allergies can be stressful – you may feel anxious about accidental exposure, or frustrated by symptoms. It is normal. The good news is that testing gives you clear answers and a plan, which can reduce worry. Talk to your doctor or a mental health professional if anxiety is affecting your daily life.

Prevention

You cannot prevent getting allergies, but you can prevent allergic reactions by avoiding known triggers. Testing helps you know what to avoid.

Vaccines

Allergy immunotherapy (often called allergy shots) is not a vaccine for an infection, but it can reduce your sensitivity to allergens. It is a treatment, not a prevention for developing allergies in the first place.

Screening programmes

There is no routine screening for allergies. Testing is done only if you have symptoms and want to find the cause.

Complications

If left untreated

• Persistent symptoms that affect sleep, work, and daily activities
• Chronic sinusitis, ear infections, or nasal polyps
• Severe allergic reactions (anaphylaxis) that can be life-threatening

Long-term outlook

The outlook for most people with allergies is very positive. With proper testing and management, you can control symptoms, avoid serious reactions, and enjoy a full, active life.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.