Skin Prick Test

Allergists order a skin prick test when a patient's history suggests an allergy but the exact trigger is unknown. It is one of the fastest ways to screen for many possible allergens in a single session.

• Allergic rhinitis (hay fever): persistent sneezing, runny nose, or itchy eyes triggered by pollen, dust mites, or animal dander
• Allergic asthma: wheezing or breathing difficulty that worsens around specific environmental triggers
• Food allergy: reactions to foods such as peanuts, tree nuts, shellfish, eggs, wheat, or cow's milk
• Allergic skin conditions: chronic hives (urticaria) or eczema (atopic dermatitis) that flare in response to allergens
• Insect venom allergy: severe reactions to bee, wasp, or ant stings

A skin prick test is one of the safest diagnostic procedures in medicine, and for most patients the discomfort is minor and brief.

• Local itching and redness at the prick sites: very common, usually fades within an hour
• Small wheals (raised bumps) at positive sites: expected and part of reading the result, but they can feel uncomfortable for a short time
• Mild swelling that lingers for a few hours beyond the test
• Rare: a more widespread skin reaction such as hives spreading beyond the test area
• Very rare: systemic allergic reaction (a whole-body response) or anaphylaxis; clinics that perform this test keep emergency medication on hand for this reason

No fasting is needed before a skin prick test. You can eat and drink normally on the day. The key preparation is stopping certain medications that can blunt the skin's reaction and produce a falsely negative result.

Your allergist will give you a specific list, but the most common drugs to pause are antihistamines (allergy tablets or syrups), some antidepressants, and certain stomach-acid medicines. Your doctor decides how many days before the test each medication should be stopped, based on how long each drug stays active in the body. Do not stop any prescribed medication without checking with the prescribing doctor first.

Wear or bring a short-sleeved top so the inner forearm is easy to access. Avoid applying lotions or creams to the test area on the day of the appointment. Smoking and alcohol do not usually need to be stopped, but your clinic may give additional guidance.

Before the test, the allergist usually reviews your symptom history, previous allergy tests, and current medications. In some clinics, a blood test called specific IgE testing may be ordered alongside or instead of the skin test, particularly if the skin test is not safe for you.

The procedure itself follows a consistent sequence, though the exact number of allergens tested varies by clinic and your symptom history.

• The skin on your forearm or back is cleaned and labelled with a pen to mark each allergen's position.

Recovery from a skin prick test is essentially immediate. Most patients leave the clinic within minutes of the result being read, with no restrictions on driving or daily activity. The test sites may remain itchy or red for up to a few hours, and the allergist may apply a mild topical cream (a cream applied directly to the skin) before you leave to ease this.

• Avoid rubbing or scratching the test area for the rest of the day to prevent further irritation.
• You can usually resume any paused antihistamines or other medications as soon as the test is complete, once your doctor confirms this.
• Showering is generally fine, but some clinics advise gentle washing of the test area for the first 24 hours.
• Watch for delayed reactions: a small number of patients develop redness or swelling at a test site several hours later. This is usually mild, but contact the clinic if it becomes very swollen or spreads.
• A follow-up appointment is typically scheduled to go through the results in detail, discuss what the positive findings mean for your daily life, and plan next steps such as allergen avoidance, medication, or allergen immunotherapy (a treatment that gradually reduces the immune system's sensitivity to the allergen).

The cost of a skin prick test varies considerably depending on where and how it is performed. A test covering a small panel of common allergens in a general clinic costs noticeably less than a broad panel run in a specialist allergy centre, and prices differ further across countries.

• Panel size: testing five common allergens costs much less than testing 30 or more. The broader the panel, the more allergen extracts, consumables, and physician time are involved.
• Specialist fee: an allergist (allergy and immunology specialist) typically charges a consultation fee on top of the test itself, whereas a general practitioner-run test may combine both into one fee.
• Hospital or clinic class: a private specialist hospital charges more than an outpatient allergy clinic, reflecting differences in overhead and nursing support.
• Country of treatment: prices differ substantially between countries, driven by local labour costs, import costs for allergen extracts, and regulatory factors.
• Additional diagnostic tests: if the allergist orders a blood test for specific IgE antibodies (proteins the immune system makes in response to allergens) alongside the skin test, this is usually billed separately.