If you are taking any medication with steroids in it, like prednisone (prednisilone in the UK and Australia), Entecort, or an inhaler with some steroidal component, then your skin reaction will be muted or entirely absent.
Your skin reaction to the first dose will be the mildest. Within ten minutes, for a few people it can take up to an hour but that is rare, you will feel a very distinctive, very strong prickling itch unlike any other you have experienced before. That is if you are not taking a drug containing a steroid, or strong anti-inflammatories or opiate pain medications.
This will last about an hour or more and will recur periodically.
It will recur every time they larvae transit some area of your body on their journey to your intestines. So on or about day four about when they transit your lungs and enter your intestinal tract in mucous from your lungs (do not expectorate from day 3-5) the rash will flare and become itchy and red again.
The same thing will happen around day 22 when they attach to your ileum for their first blood meal.
The second and third applications will produce progressively worse rashes, that can last as long as 2-3 weeks. By the fourth dose your skin reaction will have peaked and will plateau.
I saw a decline in the strength of my skin reaction after year seven, but I have no idea if this is universal, or just an artifact due to how I apply them, or the fact I am ageing, etc.
When you experience the itching on applying hookworm larvae you do so because your immune system is reacting to the fragments of enzymes, bacteria, etc., that the larvae drag into your skin when they enter. This is why your skin reaction recurs each time the larvae or mature hookworms present a strong signal to your immune system as they transit some tissues or attach to feed. The immune system has antibodies and such circulating constantly for any organism they it has targeted due to prior exposure. When they collide with the fragments of hookworms left in your skin the result in inflammation, itching, and you scratching.
As you develop antibodies your skin reaction becomes worse, though your intestinal reaction becomes better and better because of the localised anti inflammatory effect of the hookworms already resident in your ileum.
One of the reasons for this apparent contradiction (why would your skin reaction get worse while your intestinal reaction improve?) is that when hookworm moult and become infective they retain the cuticle of their L2 non infective predecessor.
It's a little like Silence of the Lambs.
So between the infective L3 larvae and the cuticle what appears on a microscope to be a tiny if not nonexistent gap is huge in terms of the size of bacteria.
Given the structure of this composite organism soaking them in some antimicrobial agent as we have like Chlorhexidine does not result in perfect sterilisation of the L3 larvae. They carry a bacterial load between their outer epithelial cells and the cuticle of their predecessor. It is this that is mostly responsible for the rash. Since none make the journey to your intestines they are not a factor in your immune response to successive doses, only hookworm are present.
We know this because when we have soaked infective larvae prior to shipping in Chlorhexidine for a really long time (days) ensuring that the larvae were in good shape before shipping or before application to my skin, the resultant rash is vastly reduced to almost non-existent.
To the point that because everyone is habituated to a strong rash if we ship larvae that are perfectly (or close to it) sterile in terms of microbes clients reject the dose as dead. Without the rash they are used to, due to bacteria, clients are certain their larvae are dead on arrival.
Applying Hookworm larvae and managing side effects
You should keep the bandage on for at least four hours, best is overnight. Once you remove it you can use any cream that works on insect bites or allergic reactions to things like poison ivy or poison oak.
I also recommend that after about day four when the skin is pruritic and crusty that you use a loofah or nail brush to remove all the loose material when you are in the bath or at the end of your shower. Doing this will almost completely stop the itching and allow the rash to heal much faster. By removing the lose dead skin, etc., containing the enzymatic fragments, bits of dead bacteria, a few cells from the cuticles of the hookworm larvae from your skin the immune system no longer has anything to react to, and the itch goes away.
Counting red bumps and why it is a bad idea
The number of red bumps and vesicles created by hookworm larvae entering your skin when you apply the bandage carrying them is not an indicator of how many entered your skin.
Some notes on application
In preparing your dose it is a good idea to apply the few microlitres of fluid containing the hookworm larvae to the bandage in two or three locations to spread them out a little so that the rash is not highly concentrated and because of that not severe because the entry points are not concentrated in one place.
Then apply some more fluid from the rinse tube to make sure they have a film of fluid through which they can easily migrate to your skin. So be sure to put the rinse tube contents on top of the places you put the fluid carrying the larvae.
It is best to apply hookworm larvae as soon as possible after receipt of the pacakge.
If they are kept in the dark, as they are in the envelope, hookworm larvae do not move at all. It is movement and activity that kill most infective larvae. L3 infective larvae have no mouth, digestive tract or evacuation point for their non-existent digestive tract. So they have to survive until they find a host on the lipids (fats) they have stored from when they were free living larvae, L2s.
The speed of chemical reactions, including those involved in the metabolism of any living organism, are dictated by the temperature they occur in. So keeping larvae cool, but never below 8°C/47°F, will help to slow their metabolic rate if you have to wait to apply them.
If you cannot use them immediately or that evening it is best to store them in a cool area of your house in a dark place.
Given the tiny amount of fluid involved and small size of each larva and the small number of larvae at each location, the larvae will be concentrated within an area a few millimetres in diameter at most at each spot on the bandage. So their entry points on the surface of your skin will be similarly spaced.
As Nottingham University discovered to their later embarrassment hookworm larvae clump together, it appears this is a deliberate evolved behaviour. Knowing that they do have gender it makes sense that they would try and aggregate together, for without at least two larvae, and one of each gender at that, reproduction will not be possible.
If they are clumped together when they are applied to the bandage they will produce one dot because their individual entry points will be so close to one another, regardless of how many are entwined. I often see four or five wrapped around one another when using the microscope.
It is for this reason that one cannot rely on a count of the red bumps and vesicles that result from the application of hookworm larvae as a guide to how many you recieved alive.
If what I have said so far is not enough to convince you, consider this.
Given their small size, they are invisible to the naked eye, even if they are not entwined if they enter your skin a distance from one another that is up to a hundred times their length they will still enter your skin less than a millimetre apart. The result would appear as one dot as the typical size of the inflamed bump produced when a hookworm larva enters your skin is more than a millimetre or two in diameter. So if the distance between individual larva entering your skin is a fraction of a millimetre the bumps they each produce will coincide significantly enough so that what are many entry points will appear as one.
Besides the fact that many bumps resulting from hookworm self-inoculation must be the result of the entry points of multiple hookworms within close proximity of one another, the only way that a dose could result in fewer hookworm larvae entering your skin than the number we ship is if some die.
I can think of no mechanism that can explain how only a few or some in a dose could die, except in very rare circumstances.
The environment formed by the micro tubes they are shipped in is so small any adverse environmental conditions that would kill one or a few larvae would almost certainly result in the death of all of them. The environment they are contained in is so small it has to be completely homogenous across its entire volume.
So if the envelope is cold (or hot) for long enough to kill one then it is almost certain that all would die. The first person to quote this to me in their order, "Aghanistan Banana Stand", gets 50% off.
Obviously, there have to be exceptions, particularly in periods of cold weather where conditions are so bad all are in the process of dying but the package arrives when only one or two are still viable.
But if you are sent 20 larvae and can count only ten or eight entry points, close examination of which will probably show a variety of sizes of dots or vesicles, you can be certain that 20 larvae have entered your skin, doing so at eight or ten closely grouped entry points each producing a single inflamed bump.
If one survives the journey it is almost certain they all did, and so long as the bandage is applied correctly to ensure the bandage is in close and tight contact with your skin with enough fluid on it to make their journey to your skin easy, then they will all be able to enter your skin.
So don't worry too much about the number of red bumps you get after applying a dose. So long as it is more than zero, particularly if the bump is very large if only one is produced, then it is almost certain all or a significant proportion of them have entered your skin.
Its not rocket science
Nor is helminthic therapy. It is not something that requires precision.
Yes, there is a magic number for each of you which makes for a therapeutic population.
But given dose sizes, and that anyone doing this who has sense is taking more than three doses, and is dosing at least once a year after the initial ramp up of 3-5 doses, the loss of one or three larvae in a single dose is not going to affect the outcome.
So stop obsessively counting the bumps on your skin, and get back to living your life and waiting for the therapeutic response that is almost certain, almost, to come given enough time.