Brief Answer:
Avoid penicillins, future allergy unpredictable

Detailed Answer:
Hello,

Thank you for asking at HCM.

I went through your history and would like to make suggestions for you as follows:

1. How likely is it to develop allergy and anaphylaxis from tamoxefin, aspirin and food?

Food allergies and drug allergies are common, but more common in children as compared to adults. Aspirin allergy is more common than that to tamoxifen.

Common foods that can cause allergy are milk, wheat, eggs, fish, shell fish, nuts, soy, peanuts, etc.

Unfortunately, there is no test available that can predict development of allergies, be it foods or drugs or other allergens.

2. Do I need certain blood tests to know if I am allergic or would develop it in the future?

Were I treating you, I would not favor such testing.

Scientifically, blood tests for allergies (that measures specific IgE levels in serum towards particular allergens) alone cannot diagnose or rule out allergies unless one has clinical symptoms.

Without clinical symptoms of allergies, blood tests or skin tests alone are not able to diagnose or rule out allergies.

So I don't think it's scientific to avoid foods or drugs solely on basis of blood/skin tests.

3. I read it could happen after years, as well after hours and not necessarily within minutes. That means I will panic till the hours pass?

Anaphylaxis usually develops within first 1-2 hours, but can develop over 24-48 hours in a few cases (late reaction).

But if you are not allergic to any particular food/drugs, I don't think you should be afraid of developing anaphylaxis.

4. Any precautions I can take apart from avoidance?

As you have mentioned that you are allergic to penicillin, you should avoid antibiotics containing penicillins. Please inform your doctor regarding your penicillin allergy.

5. Is it true that people who under-went chemo will develop a good immune system that they will not get anaphylaxis and such allergic reaction, because chemo is the most sever drug. So if you don't develop in chemo you will never get it?

As per my knowledge, people who underwent chemo do not develop severe allergic reactions/anaphylaxis because their immune system is suppressed. It does not mean it's a "good" immune system. However, this is a very generalized sentence and it very much depends upon what type of chemo you had. Your oncologist would be the best person to know the side effects of chemo agents that were prescribed to you.

To summarize,

Allergy is a disorder of immune system. Anaphylaxis is a severe allergic reaction.

As you are allergic to penicillin only, I would suggest you to avoid penicillins. As you have already been tested for allergies by foods and drugs and they are negative, no further action is required. Hope the results of allergy skin tests are interpreted by qualified and experienced allergist-immunologist.

Unfortunately, no tests are available that can predict development of allergy in future. However, if you are having any allergic symptoms currently, please let me know on follow-up. Specific testing can only be suggested after knowing symptoms in detail.

I can make suggestions for you for better immune system as follows:

1. Relaxation: Stress affects immune system adversely. So if stress is an important factor in your life, I would suggest you regular meditation and relaxation for stress-reduction.

2. Physical exercise: Regular 30-40 minutes of physical exercise under guidance of an expert helps to boost immunity.

3. Nutrition: A diet rich in vitamins & minerals and antioxidants is very useful to build a strong immunity.

Hope above suggestions will be helpful to you.

Should you have any further query, please feel free to ask at HCM.

Wish you the best of the health ahead.

Thank you & Regards

Dr Parin N Parmar

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Brief Answer:
other possibilities, please see details

Detailed Answer:
Hello,

Thank you for your follow-up.

1. Do you develop hives along with itching after approx 20 minutes of exercise?

Such reactions are one of the types of physical urticarias - cholinergic urticarias. It means rash and itching develop due to increased cholinergic activity/temperature generating activity like physical exercise, exposure to warmth, etc.

Rarely some patients may develop itching due to sweating, either irritation due to sweat or rarely true "allergy" to sweat. If you have tendency to develop sweat over thighs, this also may a possibility.

In both of the above possibilities, anaphylaxis is very very rare.

Exercise-induced anaphylaxis and food-associated exercise induced anaphylaxis are different entities from simple physical urticarias.

Physical urticaria are so common and mostly benign in population and exercise-related anaphylaxis is relatively rare.

2. I appreciate your research and understanding. Although immune system is so complicated and unpredictable, I would like to briefly reply your queries as follows:

1. There are 4 types of allergic reactions. Food allergy is type 3.

Not exactly. Food allergy, in fact can present with all 4 types of allergic reactions. Most common are type 1 (urticaria, anaphylaxis, angioedema, stomach symptoms, etc) and type 4 (some delayed reactions), but rarely 2 and 3 types are also seen.

2. Of course it takes time to develop sensitization and an allergic response. So initial food-related symptoms may be mild. It's always good to observe self for any symptoms caused by foods.

However, in practice, food related symptoms are more often non-allergic in nature rather than allergic. Without consultation of allergist-immunologist and support by investigations, it is very difficult to differentiate non-allergic reactions from allergic reactions.

Sometimes, anaphylaxis can present suddenly as well, for unexplained reasons.

3. Sensitization and memory are important in development of all types of allergies but it has nothing to do with "good" or "bad" food. An immune system can become sensitized to any particular food at any time and thereafter may start reacting towards it. This whole process, however, is unpredictable in many aspects.

Of course, all over, food allergies are very common in children and they tend to improve by themselves with increasing age.

I would like to repeat here, that without developing reactions to any particular foods, it is not scientific to avoid foods based on any allergy testing. Allergy tests have their own pros and cons and are not 100% to predict any allergy without support of detailed symptom history.

4. In first query, you had mentioned about skin test and low bumps caused by testing. Was it an allergy skin testing? I would like to know the exact results (which allergens were tested, what was the size of bumps, what was to conclusion, etc) before making comment on sinus allergy.

Sinus symptoms have many causes simultaneously operating, like, allergy, infection, untreated/partly treated nose symptoms, environmental factors, etc etc.

Allergy alone cannot cause all sinus problems unless allergic rhinitis was not treated in the best way.

Again, generally, respiratory allergies (sinus, rhinitis, asthma, etc) are caused by air-borne allergens while anaphylaxis is more common with food, drugs, etc. It's too rare to see anaphylaxis from air-borne allergens.

I can understand your concern about gaining weight. If you are not allergic to any particular food at present, in my opinion, you can take all foods. If you are experiencing symptoms from particular foods, you may consult an allergist-immunologist, get tested for those foods and decide after allergist's opinion.

Hope above information will be helpful to you.

Should you have any further query, please feel free to ask on follow-up.

Wish you the best of the health ahead.

Thank you & Regards,

Dr Parin N Parmar

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