Condition: Lice (Fig. 1) in the hair of the host principally around the
ears and back of the head (occiput).
Have you ever been accosted by a person that is afflicted with lice or mites on their body? Most specimens submitted for identification are, "from their brother, sister or roommate" and they need to know, "what this person can do to correct the situation." Most people are reluctant to admit they harbor lice or mites and usually pose as ambassadors for a close acquaintance, anxiously listening to every word one speaks. I suppose this is a normal behavior trait; however, it isn`t a shame for one to be afflicted with lice or mites, but it is a shame to keep them.
Control recommendations (Table 1) for many insect and mite cases should be prescribed by a medical doctor since a lay person cannot prescribe "medicine" for people. There are certain over-the-counter concoctions that one may suggest a person use. It is also suggested that he or she consult with their pharmacist concerning available products.
The following brief outline, for some common insect and mites of humans, will provide some basic information for specific problems.
Condition: Lice (Fig. 1) in the hair of the host principally around the
ears and back of the head (occiput).
How it is spread: Close contact under crowded conditions such as elementary school classrooms.
Corrective measures: The continued presence of lice on the head is inexcusable. Several commercial formulations are available (Table 1) and one or two applications will completely eliminate lice on the human body. The use of soap and water in washing the hair is ineffective. Compounds containing pyrethrins will adequately destroy lice in a short time. It should be noted that if one member of the family harbors lice, usually it`s a good practice that all family members be treated. See the Texas Agricultural Extension Service publication, "Human lice" L-1315, for more information.
Table 1. Partial listing of insecticidal and miticidal products for use to control common pests on humans and infested premises.
| Product | Ingredient | Formulation | Target |
|---|---|---|---|
| Commercial products for louse and mite control on humans | |||
| Kwell® (Prescription only) | Lindane 1% | Cream Lotion Shampoo | Scabies mite Head louse Crab louse |
| Eurax® (Prescription only) | Crotamiton | Cream Lotion | Scabies mite |
| Over-the-counter products | |||
| A-200 Pyrinate® | Pyrenthrins | Shampoo | Head louse Body louse Crab louse |
| Rid® | Pyrenthrins | Shampoo | Head louse Body louse Crab louse |
| Cuprex® | Tetrahydronaphthalene | Shampoo | Head louse Body louse Crab louse |
| Bedding materil only -- DO NOT USE ON HUMANS | |||
| R&C® Spray | Phenoxybenzyl and other compunds | Spray | For objects infested with lice or louse eggs |
Condition: This louse, appearing similar to the head louse (Fig. 1), is common in clothing and usually stays in areas where the clothing is in close contact with the body such as underwear, forks of the trousers, armpits, waistline, neck and shoulders. In heavy infestations, some lice may remain on the body after the clothing is removed. Eggs are usually deposited in the seams of the clothing, but may also be attached to coarse body hairs.
The body louse was a rather infamous insect during World War I when it received such nicknames as the cootie, the grayback, and then during World War II, was probably more aptly named, mechanized dandruff. The term mechanized dandruff comes from the fact that many of the people in Italy afflicted with this louse wore loosely knit clothing, and the lice could be seen running in and out of the weaves of the clothing, hence the term mechanized dandruff.
How it is spread: Close contact with humans harboring the lice or wearing clothing containing eggs.
Corrective measures: Bathing or shampooing with soap and water will not remove all nits from hair or will not remove lice attached to the body. Clothing and bedding should be laundered in hot, soapy water at 125o F. or over for a minimum of 10 minutes, or be dry cleaned. Lice can be controlled on the body quite easily by commercial preparations containing pyrethrins or certain other medications available as dusts, lotions, ointments or shampoos (Table 1). See the Texas Agricultural Extension Service publication, "Human lice" L-1315, for more information.
Condition: Lice (Fig. 2) attached to hair on legs and pubic region.
How it is spread: Close, intimate contact with humans harboring this louse.
Corrective measures: Bathing or the use of shampoos, again, will not control this or other lice. Medications available as shampoos or lotions will effectively rid a person of crab lice if the control attempt is taken seriously (Table 1).
Apply the medication over the entire hairy parts of the body and repeat this at least one time within a 4 or 5 day period. Repeat applications for controlling lice are important to control small lice that have just emerged from eggs that were not killed by the first treatment. See the Texas Agricultural Extension Service publication, "Human lice" L-1315, for more information.
Condition: Chigoe fleas (Fig. 3) produce nodular swellings and ulcers usually around toenails, between the toes and soles of the feet.
How it is spread: Walking barefooted is an excellent way to acquire this flea in areas where this flea occurs.
Corrective measures: The chigoe flea usually attacks bare feet. The fleas, more or less, burrow into the skin of the host causing a nodular swelling that ulcerates. In reality, the insect cannot burrow. For some reason, the skin near the flea mouth parts almost totally envelopes the flea, giving rise to skin nodules. In all probability, this insect should be treated by a physician since often time the fleas must be removed surgically by sterile needles or knife blades. Fortunately, this flea is not too common in South Texas. It does occur; however, in the tropical and sub-tropical regions of North and South America.
Condition: Scabies (Fig. 4) or 7-year itch.
How it is spread: Close or intimate contact such as sleeping in the bed with an infested person or in very crowded conditions where body contact occurs.
Corrective measures: It takes a long time for persons infested with scabies mites to develop symptoms such as a rash or itching. It is normally recommended that the patient and all the family members who have had close contacts to be treated at the same time. Currently medications available include Kwell shampoo, which contains 1% lindane and 10% crotamiton (Eurax). These preparations are available in creams or lotions and should be used according to a physicians instructions instructions. Usually the medication is applied at bedtime and then thoroughly rinsed off the following morning. It`s recommended that a second treatment about one week later be applied to eliminate newly hatched mites before they are able to mature and lay eggs. Itching from scabies usually persists for a long time due to allergic reactions produced by the mites but this does not indicate that further treatments would be necessary.
Condition: Chiggers (Fig. 5) produce red welts or bumps on the body, usually accompanied by intense itching.
How it is spread: It is not spread form human to human, rather people acquire chiggers by walking in grassy areas where chiggers occur.
Corrective measures: Chiggers are the larval stage of a certain type of mite that only requires blood from humans during the larval stage. Usually by the time one is aware that he has a chigger, after the welt or bump and the accompanying itching occur, the chigger has probably left the host. Corrective measures include lotions to reduce the itching of the mite and, if possible, avoid scratching chigger bites. Scratching will often allow bacteria to be mechanically rubbed into the would which leads to secondary infections. There are certain chemical sprays available that one could apply to boots and trouser legs when in the woods; however, these should be used sparingly, especially on children. See the Texas Agricultural Extension Service publication, "Chiggers" L-1223, for more information.
Condition: Follicle mites (Fig. 6) possibility cause an acne-like condition around the eyebrows or around the nose.
How it is spread: Evidentially through close contact.
Corrective measures: Although this mite has been incriminated with things such as acne and blackheads, it does not affect most people. It has been found on people throughout the world without any ill effects to the host.
Condition: Tropical rat mites (Fig. 7) cause dermatosis or possibly skin irritations.
How it is spread: In dwellings or in dwellings where rats and mice are known to occur.
Corrective measures: There are several miticides that may be applied inside the home by a professional pest control operator; however, rodent control is one of the prime requisites to rid a dwelling of this mite. Houses or dwellings should be made rat proof and an intense rodent trapping or poisoning program must be initiated to get rid of the host. The tropical rat mite will travel some distance from rat burrows to attack humans and the bite is painful and produces a sharp itching pain.
Condition: Myiasis. This term relates to the maggot or larval stages of flies that inhabit humans or animals.
How it is spread: Only by adult flies laying eggs on hairs of the host.
Corrective measures: Although rare, the cattle grub which attack cattle will live in human tissues. The larvae follow migratory routes similar to those in cattle and take one year to complete a life cycle. Repeating that the cattle grub is usually accidental and rarely found in humans, there was one case reported by a researcher by the name of Herms in 1925 that involved the foreman of a ranch who acquired two or three eggs of the cattle grub and experienced sharp pain throughout his body as the larvae migrated around the tissue. Corrective measures in this case would be preventive and involves avoiding bot flies, particularly during the spring of the year. Do not catch or collect any of these insects by hand.
In relation to myiasis, it should be noted that one can find 134 species of flies which can cause various types of myiasis in man. This is a long and lengthy list, but in most societies this is uncommon; however, in some of the more primitive societies myiasis occurs frequently.
Condition: Myiasis - maggot or larval stages of flies that inhabit humans or animals.
How it is spread: Only through egg laying of adult flies.
Corrective measures: Medical attention must be sought in cases with individuals harboring screwworms. Screwworms (Fig. 8) have been recovered from wounds in humans.
Condition: Myiasis - maggot or larval stages of flies that inhabit humans
or animals.
How it is spread: The adult human bot fly actually captures insects that feed on man, such as a mosquito, then weighs it to the ground and lays its eggs on the underneath side of the abdomen (Fig. 9). When the mosquito feeds on man, the eggs hatch and the larvae crawl down onto the skin, evidentially triggered by heat, and burrow into the tissue. This insect does not occur in the United States; however, in areas where it does occur it can be quite a problem. Human bot fly larvae do not migrate throughout the tissue, rather than stay in one general area until the life cycle is complete.
Dr. L. H. Dunn in the 1930`s successfully reared several larvae of the human bot fly in his arm! This really requires more dedication than the author has; however, if you are interested in reading about this, it occurs in Psyche, vol 28, pages 327-342.
There are several other arthropods which affect man. Most of them do not stay on man for any length of time. This list includes various ticks, kissing bugs, bed bugs, mosquitoes, gnats, midges, human fleas and other types of biting flies such as horse flies and deer flies. For additional information, see the following Texas Agricultural Extension Service publications:
There is a mental condition in man associated with insects termed entomophobia. Entomophobiacs have an inordinate fear of insects, either real or imagined, sometimes to the point of developing neurosis or psychosis. If you are confronted with a person afflicted with this disorder, lend a listening ear, do not make fun of their situation or do not make light of their situation, because whether the insects are real or not, they are indeed real to them. Many of these people may require psychiatric care and if possible, refer them to a professional entomologist, a dermatologist or a psychiatrist, the latter of which is the most difficult to get them to see because to them the problem is simply a matter of ridding them of a nuisance insect. They will be the last person to admit their problem is mental.
The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied.
Educational programs conducted by the Texas Agricultural
Extension Service are open to all people without regard to race,
color, sex, disability, religion, age or national origin.
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Last modified: March 18, 1997 by Edgar Cross