Brief Answer:
Chronic pruritus

Detailed Answer:
Hello and welcome,

I sympathize with you completely as I have experienced intermittent prolonged episodes of generalized pruritus (itching). It is nerve-racking.

I see that you live in Australia and I don't know the healthcare system there (I am in US), but I would advise you to find a medical facility of higher learning such as a large well established university hospital for a consultation with an allergy/immunology physician. Even if you have to travel a distance for the initial consult, and then the physician there can advise your own local doctor in continued care it would be worth it. But call the allergy-immunology department first to make sure that they have faculty doctors who are experts in pruritus that has been refractory/resistant to treatment.

The thing I have found in dealing with my own pruritus is that this is not an area that has been well studied or that most general allergists have a lot of knowledge and experience with.

There are protocols for dealing with chronic urticaria (ongoing hives) and these are generally the same as for chronic itching. But chronic itching can be from underlying medical problems, including thyroid disease, autoimmune disorders, leukemia and lymphoma, so make sure these have been ruled out first (with blood tests and physical exam).

The protocol advised by the AAAAI (allergy association in the US) is a step wise system as follows:

STEP 1:
Treatment with just one 2nd generation antihistamine, such as Zyrtec. Avoid things that make the symptoms worse.

STEP 2:
1. Increase the dose of the 2nd generation antihistamine used in Step 1. For example, increase Zyrtec from 10 mg once a day to 4-6 10 mg tabs a day.

2. Add another (different) second generation antihistamine (e.g. fexofenadine or loratadine).

3. Add an H2 blocker (Explanation: regular antihistamines are H1 blockers. H2 blockers, such as ranitidine, are stomach acid blockers. But some skin histamine receptors are H2 receptors. Most are H1, but the H2blocker medicine can help block histamine from those lesser number of receptors that are H2.) In the US, a common H2 blocker is Zantac. Generic is ranitidine. Can take up to 150 mg twice a day. Unlike regular antihistamines, higher doses of H2 blockers do not help more.

4. Add a leukotriene receptor antagonist. Montelukast is the generic name, Singulair is a brand name.

5. Add a 1st generation antihistamine to be taken at bedtime (such as hydroxyzine, or doxepin). These are very sedating.

STEP 3:
Higher dosing of potent antihistamines (doxepin or hydroxyzine)

STEP 4:
Add on alternative agents such as anti-inflammatory agents, immunosuppressives (cyclosporin), or biological agents (omalizumab). This step would require close monitoring and should be done under consultation of an experienced allergy/immunology physician.

So that is how it is managed here.

But before preceding further, if it hasn't already been done, get a test for TSH, thyroxine, thyroid auto-antibiodies, sedimentation rate (ESR) which shows if there is inflammation happening in the body, ANA (for autoimmune disorders), CBC with full peripheral smear, and Tryptase level (see below for explanation of this).

There is some thinking that there are people with Mast Cell Activation Syndrome. There isn't much research on this yet - more on Masocytosis, which is a problem of the bone marrow. But MCAS is something new coming up in the literature where one's mast cells, which contain histamine, are overly sensitive or reactive. An elevated Tryptase level test can be indicative of this being a problem - but not always.

If you notice certain foods or preparation/storage of them (such as canning) bother you more, avoid these. There is some thought that certain foods can cause higher releases of histamine even without the recipient actually being allergic to that food. But this is not well studied.

I hope this information helps. I feel for you!

Please let me know if I can provide further information or clarification.

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Brief Answer:
Next step

Detailed Answer:
From the list of medications you are on, it looks like you are already on a variety of 1st and 2nd generation antihistamines. If they do not relieve the itching the next thing to do is add montelukast and ranitidine.

Montelukast 10 mg per day

Ranitidine 150 mg twice a day

You may need a prescription from a doctor for these, but these would be the next step.

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