Theory No 1

Last updated: 23 Jan 2012

Of course, since I’ve been diagnosed with delusional parasitosis, any theories I come up with would be described by the doctors as part as my psychosis.

But here’s something I think could be my mystery tormentor: I’ve only been able to find one species of animal that produces plugs in hair follicles and sebaceous glands – the human demodex mites (demodex folliculorum and demodex brevis).

Demodex folliculorum, as its name suggests, is found in hair and eyelash follicles associated with pilosebaceous glands in the eye or elsewhere on the face and body. It usually lives with its head buried inside and tail protruding. There can be as many as 25 to a follicle. The females make their homes there, while the males wander from follicle to follicle looking for females to impregnate. Sex takes place at the opening of the follicle only at night, while the host sleeps - or at least that’s what medical research would have us believe.

I believe this is patent nonsense. And it’s lazy research devoid of any intelligence or intuitition whatsoever. Any demodicosis sufferer knows that demodex mites are active during daylight hours - indoors, and outdoors under their clothing. I can reliably stop tickle activity on my head during the day by going out into sunlight. But if I wear a hat it will continue on my scalp.

Here’s why: ultraviolet light is extremely damaging to them. It’s what give us humans a suntan. But you don’t tan under your clothes, do you? Nor do you tan indoors. The truth is that demodex activity has absolutely nothing to do with clock time. it's the relative absence of light containing strong ultraviolet rays that allows them to become active - at any time of the day or night.

Demodex Folliculorum image © Science Photo Library, author Steve G Schmeissner.

In my scalp.

Demodex folliculorum
Demodex folliculorum, male top, female below. Image from
Catalogue of Organisms.

Demodex brevis lives alone in the body’s sebaceous glands and feeds on the tissue as well as the oil produced by the gland. It also lives in the meibomian gland and the gland of Zeis.

Demodex brevis
Demodex brevis, male left, female right.
Image from
Catalogue of Organisms.

Removed carefully from my anus after tickle (image cropped for clarity).

Researchers generally agree that the lifespan of male mites is no more than 15 days (with one claiming 2-4 weeks). But estimates of female lifespans vary depending on whose research paper you read - from 15 to 24 to 60 days. If a mite is dislodged from the host, some researchers claim it will take from 24 to 38 hours to die. Others say that if the environment is dry, it will die in a few hours. But in a moist environment, like a just-used towel, it can survive for up to 58 hours.

Locomotion speeds of 8-16cm (3.1-6.3ins) per hour are also generally agreed. One paper, published by the NIMH, gives a speed of 8-16mm per hour. I must be charitable here and assume this is a typographical error. Nevertheless, it calls into question the quality not only of proofreading, but also of peer review.

Overall, when it comes to demodex, one is left to wonder if these people are actually researching the same insect or just plucking numbers out of the air.

Every human on the planet, except for newborn infants, hosts a population of both of these types of demodex. Normally, the body’s immune system keeps them under control so they don’t bother us. They can only be transmitted through prolonged skin-to-skin contact. If this happens, it should cause no problem for someone with a normal healthy immune system. (Note that virtually every furred mammal species hosts its own variant of demodex. It is believed that these do not transfer successfully to human hosts. But cases of doggie demodex infesting a human have been documented in veterinary workers.

If the human immune system becomes compromised (immunosuppression), however, your own demodex mites can cause a problem.

Normally, the problem, called demodicosis, only extends to the eyelashes, eyebrows, nose, cheeks, chin, temples, and forehead. But in a particularly florid infestation, there’s nothing to stop them taking over your hair follicles and sebaceous glands from head to toe. They’re also implicated in rosacea, acne and dry eye syndrome.

  • The Medscape Reference Library has an interesting article on human demodicosis written by Manolette R. Roque, MD, MBA.
  • The Journal of Clinical and Aesthetic Dermatology also has a good study on demodex dermatitis by Joseph B. Bikowski, MD, FAAD and James Q. Del Rosso, DO, FAOCD.
Unfortunately, both articles detail treatment plans for patients with facial/head symptoms only, probably because medicine doesn’t believe humans can contract it elsewhere. I don’t believe these are suitable for generalised demodicosis.

If you find my situation difficult to credit, please remember that these mites have now had almost three years to proliferate unhindered. And here’s the main reason why:

The most well-known human immune deficiency disorder is HIV/AIDS, and sufferers are particularly prone to parasite infestation. However, the immune system can also be damaged by stress and lack of sleep coupled with a bad diet.

My Stress

For four months prior to the onset of my mother’s illness, I put myself under enormous stress studying for an advanced video editing qualification. I felt I just had to pass that exam since a lot of money had been paid for the course. In the event, I did.

Almost immediately after, it became apparent that my mother was very ill. Her doctor kept diagnosing ‘flu even though she always got the vaccine every year. More stress.

Her unexplained and unresolved delirium made her illness and death the most distressing experience of my life.

Then came the bedbugs, fleas, and scabies. Stress piled upon stress.

And finally, when at last I’d beaten them, the tickles, the dermatologists, and the delusional parasitosis diagnosis. (Which, incidentally, gave these things yet another year to reproduce and spread even further). The stress continued to build.

With all the disruption and the pesticides, the exhaustion from lack of sleep, constant washing, vacuuming, and cleaning, and the “yuck factor” that goes with a severe home infestation, I could do very little cooking for myself. So I lived on takeaway and convenience food for much of that time. And my immune system has obviously paid for all this. Because I live alone and have avoided socialising, I didn’t pick up any of the normal social infections like colds or ‘flu.

I’ve detailed my sleep problems on this page, so I won’t repeat them here.

Does demodicosis fit the symptoms?

1. Tickles and some itching in the following places:
  • Head: (almost incessantly) around eyes and orbital ridges, eyebrows, cheeks, nose, nostril entrances, chin, forehead, temples, scalp, ears, ear canals, neck.
  • Trunk: (frequently) shoulders, chest, armpits, arms, back of hands and fingers, back, hips, abdomen, groin, scrotum, perineum, buttocks, anus.
  • Legs: (frequently) thighs, behind knees, shins, calves, feet, toes.
I think two things cause the tickles:
  • Wandering males and virgin females (both types of mites).
  • The insects’ struggles to exit the plug can cause the entire thing to be pushed out onto the surface of my skin, thus registering its sudden presence as a foreign body – a tickle, something to be brushed off. I believe this can also cause the popping sensation referred to below. Here’s a freshly-ejected plug:

A plug that’s just been ejected on my forehead. The larva can be seen breaking through the wall at the top.

2. Popping and hair-flick sensations like a soap bubble popping on my skin or a single hair being flicked:

  • Scalp and eyebrows: (frequently) these seem to be the main areas I get pops and hair-flicks.
  • Trunk: (infrequently) mostly abdomen, shoulders, arms, and back of hands and fingers.
I think these sensations could be caused by three things:
  • Pops: the plug being suddenly dislodged out of the skin onto the surface by the insects’ struggles.
  • Pops: Demodex brevis breaking through the external wall of an embedded plug.
  • Hair-flick: Demodex follicularum entering or exiting a follicle, causing the hair to move.

3. Sharp pain (or “sting” sensation) exactly like a hair being tugged hard (not as common as tickles or pops) in these areas:
  • Legs: (frequently) thighs.
  • Trunk: (infrequently) chest, armpits, abdomen, groin, scrotum, anus, back, hips, buttocks.
I think this may be caused by the mites’ initial entrance into a follicle, then moving about inside, putting pressure on the muscle and nerve. It could also be due to the fact that demodex mites also have a sharp needle-like “tooth” in their mouth parts which they use to pierce flesh.

Here’s a sequence of shots of my inner left thigh (full-size versions will open in a new window by clicking on an image).

20111029_122202261-27% 20111029_122645114-27%
Pictures 1 and 2.

20111029_122844953-27% 20111029_123012093-27%
Pictures 3 and 4.

Picture 1 is the inflamed follicle about an hour or so after the initial “hair-tug” pain. Picture 2 shows sebum outflow after the pale green top was punctured (black spots are soot from a sewing needle sterilised with a lighter). Picture 3 shows the results of deep-squeezing the site – an insect (or partial insect) is visible at the bottom in the serum. Picture 4 is after clean-up – notice the hair is now gone.

4. I’m shedding inordinate amounts of dead, dry skin from every part of my body. I never had this problem before, not even dandruff. It persists despite trying three different moisturisers.

I think this is caused by the plugs blocking the sebaceous glands and follicles, preventing the outflow of oil necessary to soften and lubricate the skin.

Is demodex the villain? Or something else?
Read on to continue the story...