Certain medications can mask your skin's reaction and cause us to miss real allergies. Please review this list carefully and stop the medications below on the timeline shown. If you're unsure about any medication you take, call us before stopping anything.
Stop ALL antihistamines 7 days before your appointment.
This includes pills, liquids, eye drops, nasal sprays, and any cold or sleep product that contains an antihistamine. If you take an antihistamine within 7 days of your test, your results may not be accurate and we may need to reschedule.
1. Oral antihistamines — stop 7 days before
Brand names below are common examples — not a complete list. If a product label says it treats allergies, hives, itching, or sleep, assume it contains an antihistamine.
| Generic name | Common brand names |
|---|---|
| Cetirizine | Zyrtec, Children's Zyrtec, Zyrtec Allergy |
| Levocetirizine | Xyzal, Xyzal Allergy 24HR |
| Loratadine | Claritin, Alavert, Children's Claritin |
| Desloratadine | Clarinex |
| Fexofenadine | Allegra, Allegra Allergy, Mucinex Allergy |
| Diphenhydramine | Benadryl, ZzzQuil, Sominex, Tylenol PM, Advil PM |
| Doxylamine | Unisom SleepTabs, NyQuil |
| Chlorpheniramine | Chlor-Trimeton, Aller-Chlor |
| Brompheniramine | Dimetapp, Children's Dimetapp Cold |
| Hydroxyzine | Atarax, Vistaril |
| Cyproheptadine | Periactin |
| Promethazine | Phenergan |
| Meclizine | Antivert, Bonine, Dramamine Less Drowsy |
| Dimenhydrinate | Dramamine Original |
2. Combination cold, sleep & allergy products — stop 7 days before
These contain antihistamines even if "allergy" isn't on the front of the box.
| Generic combo | Common brand names |
|---|---|
| Cetirizine + pseudoephedrine | Zyrtec-D |
| Loratadine + pseudoephedrine | Claritin-D |
| Fexofenadine + pseudoephedrine | Allegra-D |
| Acetaminophen + diphenhydramine | Tylenol PM, Tylenol Severe Cold + Flu Nighttime |
| Ibuprofen + diphenhydramine | Advil PM, Motrin PM |
| Cold/flu nighttime blends | NyQuil, Theraflu Nighttime, Robitussin Nighttime |
3. Antihistamine eye drops & nasal sprays — stop 7 days before
| Generic name | Common brand names |
|---|---|
| Olopatadine (eye) | Pataday, Patanol, Pazeo |
| Ketotifen (eye) | Zaditor, Alaway, Claritin Eye |
| Azelastine (eye) | Optivar |
| Epinastine (eye) | Elestat |
| Bepotastine (eye) | Bepreve |
| Azelastine (nasal) | Astepro, Astelin, Astepro Allergy |
| Olopatadine (nasal) | Patanase |
| Azelastine + fluticasone (nasal) | Dymista |
4. Other medications with timing
Some medications also affect testing but on a different timeline. Stop these only if your prescriber agrees.
| Medication class | Stop how long before testing? |
|---|---|
| H2 blockers — famotidine (Pepcid), cimetidine (Tagamet), nizatidine (Axid) | Stop 2 days before |
| Tricyclic antidepressants — amitriptyline (Elavil), nortriptyline (Pamelor), imipramine (Tofranil) | Stop 7 days before — only with your prescriber's approval |
| Doxepin (Silenor, Sinequan, Prudoxin cream) | Stop 14 days before — strong antihistamine effect; check with your prescriber |
| Mirtazapine (Remeron) | Stop 7 days before — only with your prescriber's approval |
| Sleep aids with antihistamines — Unisom, ZzzQuil, Tylenol PM, Advil PM | Stop 7 days before |
| Topical steroid creams on the testing area (back/forearms) | Stop 7 days before |
| Omalizumab (Xolair), dupilumab (Dupixent), and other biologics | Tell us before scheduling — testing may need to be delayed |
5. Keep taking — but tell us about these
| Medication | Why we need to know — but do NOT stop on your own |
|---|---|
| Asthma inhalers — albuterol, Symbicort, Advair, Trelegy, Breo | Keep taking. These do not affect skin testing. |
| Nasal steroid sprays (Flonase, Nasacort, Rhinocort, Nasonex) | Keep taking. These do not affect skin testing. |
| Montelukast (Singulair) | Keep taking — does not interfere with skin prick testing. |
| Beta blockers (metoprolol, atenolol, propranolol, carvedilol, timolol eye drops) | Tell us before testing. Do NOT stop on your own — your prescriber must guide any change. |
| Oral corticosteroids (prednisone, methylprednisolone) | Let us know your dose. Short courses or low doses are usually fine. |
| Daily prescription medications not listed above | Bring your medication list. We'll review it together. |
Never stop a prescription medication on your own.
If you take a medication on this list that requires prescriber approval to pause (antidepressants, beta blockers, biologics), call our office at (727) 446-1097. We'll work with you and your prescriber to find a safe plan — sometimes we adjust the test instead of the medication.
About the Skin Prick Test
The skin prick test (also called a scratch test or puncture test) is the gold-standard, in-office way to identify environmental and food allergies. It is fast, safe, and gives us answers in about 20 minutes.
How it works
- We place small drops of allergen extracts (such as tree pollens, grasses, weeds, dust mite, mold, pet dander, and selected foods) on your upper back. We use the forearm only when the back isn't accessible.
- Using a tiny plastic applicator, we lightly scratch the surface of the skin through each drop. The scratches do not draw blood and most patients describe them as mildly ticklish, not painful.
- We also place two control drops: a positive control (histamine) to confirm your skin can react, and a negative control (saline) to rule out skin sensitivity unrelated to allergy.
- After about 15–20 minutes, we measure any raised bumps ("wheals"). A positive reaction looks like a small mosquito bite at the test site.
- After the prick test is read, we typically follow up the same visit with intradermal testing on the arm (see below).
Intradermal testing
After your skin prick test, we usually perform a series of intradermal tests on your upper outer arm. Intradermal testing is a more sensitive way to detect milder allergies that the prick test alone can miss. Because we'd rather not overlook something that's contributing to your symptoms, we test thoroughly.
- A very small amount of each allergen is injected just below the surface of the skin using a thin needle, creating a tiny bubble ("bleb").
- We typically place a number of intradermal tests so we get a complete picture before making treatment recommendations.
- Most patients tolerate these well — a quick pinch at each site, then mild itching that fades within an hour or two.
- After 15–20 minutes, we measure each site the same way we read the prick test. The wheal pattern tells us which allergens you're truly sensitive to and at what level.
How long it takes
Plan for about 60 minutes in the office for the testing visit. This includes a brief history review, the prick test, the reading window, and the intradermal testing.
Is it safe?
Skin prick testing is very safe and is appropriate for both children and adults. Mild itching at the test sites is common and usually fades within an hour. Serious reactions are rare; our team is trained and equipped to manage any reaction immediately if one were to occur.
How to prepare on the day of testing
- Wear a top that can easily come off or open in the back. We test on your upper back; intradermals go on your upper outer arm, so easy access to both helps.
- Skip lotions, moisturizers, oils, and sunscreen on your back, chest, and arms the morning of your visit.
- Eat normally and take your non-antihistamine medications as usual.
- Bring a current list of all your medications, including over-the-counter products and supplements.
- If you have a fever, active rash on the testing area, or significant eczema flare, call us — we may reschedule for accuracy.
After your test
- Mild itching at the test sites is normal for an hour or two. A cool compress or hydrocortisone cream can help.
- Once testing is complete, you may resume your usual antihistamines unless we tell you otherwise.
- We do not review your results on the same day as the test. You'll come back for a separate "skin test talk" visit, where Dr. Reller walks you through your results and what they mean for you.
- At your skin test talk, we'll discuss your treatment options together — which may include allergen avoidance, targeted medications, allergy shots (SCIT, subcutaneous immunotherapy), or allergy drops (SLIT, sublingual immunotherapy).
Common questions before your visit
Most patients have the same handful of questions. Here are the answers — we hope these save you a phone call.
| Question | Answer |
|---|---|
| I accidentally took an antihistamine within the 7-day window. | Call us at (727) 446-1097 before your appointment. Depending on how recently you took it, we may move your visit out a few days so the test is accurate. It's better to reschedule than to test on a masked result. |
| Can I take Tylenol, Advil, or aspirin? | Yes. Plain Tylenol (acetaminophen), Advil/Motrin (ibuprofen), Aleve (naproxen), and aspirin are fine. Avoid the "PM" or nighttime versions — those contain antihistamines. |
| What about my vitamins, birth control, or supplements? | Most are safe. Bring your full list (including herbals and CBD) and we'll review it together at the visit. |
| Should I eat or drink before testing? | Yes. Eat normally and stay hydrated. Skipping meals can make you feel lightheaded during the visit. |
| Can I shower the morning of testing? | Yes — just skip lotion, body oil, and sunscreen on your back, chest, and arms. |
| I have a cold, fever, or rash on my back or arms. | Call us. A mild cold is usually fine, but a fever or active rash on the testing area means we'll reschedule for a clean read. |
| I'm pregnant or breastfeeding. | Tell us before scheduling. Standard environmental skin testing is generally postponed during pregnancy. We can usually proceed while breastfeeding — we'll talk through timing. |
| Can my child be tested? | Yes — children of all ages can be tested. A parent or guardian must stay throughout the visit. |
| Can I drive home or go back to work afterward? | Yes, in nearly all cases. The test does not make you drowsy. |
| Will the test sites scar? | No. The marks are tiny and fade within a day or two. There are no permanent marks. |
Common questions after your visit
| Question | Answer |
|---|---|
| When and how do I get my results? | At a separate "skin test talk" follow-up visit. Please schedule it before you leave today so you don't have to call back. |
| I forgot to schedule the skin test talk. | Call our office at (727) 446-1097 to set it up. That's where Dr. Reller goes through your results and your treatment plan in detail. |
| Can I shower or get the test sites wet? | Yes, after about 2 hours. Use plain water and don't scrub the area for the rest of the day. |
| It still itches — can I scratch? | Try not to. Scratching can make the area more irritated. Use a cool compress or 1% hydrocortisone cream instead. |
| Can I exercise, swim, or be in the sun today? | Yes, once testing is complete. Sweat and sun won't affect your results, but skip hot tubs and rough scrubs for the day. |
| I'm noticing a bump or itching at the intradermal sites 24–48 hours later. | This is occasionally seen with intradermal testing and is usually a delayed reaction, not an emergency. Call us at (727) 446-1097 to describe it; we like to know about these so we can document them. |
| When can I restart my regular antihistamines? | As soon as testing is complete, unless we tell you otherwise. |
| I have an EpiPen — do I need to use it after testing? | Almost never — but if you ever have any of the emergency symptoms listed below, use your EpiPen first, then call 911. |
When to call us after your test
Most people feel completely normal within an hour or two of testing — just a little itchy at the test sites. Reactions beyond the test sites are uncommon, but if they happen they usually appear within a few hours. Use the guide below.
What's normal
- Small red, raised bumps ("wheals") at the test sites for 30–60 minutes.
- Mild itching at the test sites for 1–2 hours, occasionally up to a day.
- Faint pink marks where the applicator touched the skin, fading over the day.
Call our office at (727) 446-1097 if you notice
- Hives, rash, or itching that spreads beyond the test area.
- Test sites that are still very red, swollen, or itchy more than 24 hours later.
- New nasal congestion, runny nose, sneezing, or itchy/watery eyes that started after the test.
- Mild stomach upset, nausea, or feeling "off" within a few hours of the test.
- Any reaction that worries you — even if you're not sure it's related, we'd rather hear from you.
Call 911 or go to the nearest ER right away if you have:
- Trouble breathing, wheezing, or chest tightness
- Swelling of the lips, tongue, throat, or face
- Tightness in the throat or trouble swallowing
- Sudden widespread hives
- Dizziness, fainting, or feeling like you might pass out
- Repeated vomiting or severe abdominal pain
If you have prescribed epinephrine (EpiPen, Auvi-Q), use it FIRST, then call 911. Do not drive yourself.
After hours: if your symptoms are not an emergency but you're concerned, leave a message at (727) 446-1097 and our on-call team will return your call. For anything urgent, do not wait — call 911 or go to the nearest emergency department.
Questions before your appointment?
Call Clearwater Family Medicine & Allergy at (727) 446-1097. We're happy to review your medication list with you so you arrive ready and confident on test day.
