The condition is diagnosed by finding live lice in the hair. Finding empty eggs is not enough. This is made easier by using a magnifying glass or running a comb through the child's hair. In questionable cases, a child can be referred to a health professional. However, the condition is overdiagnosed, with extinct infestations being mistaken for active ones. As a result, lice-killing treatments are more often used on noninfested than infested children. The use of a louse comb is the most effective way to detect living lice. With both methods, special attention should be paid to the area near the ears and the nape of the neck. The use of a magnifying glass to examine the material collected between the teeth of the comb could prevent misdiagnosis.

The presence of nits alone, however, is not an accurate indicator of an active head louse infestation. Generally, white nits are empty egg casings, while brown nits may still contain viable louse larva. One way of determining the nit is to squeeze it between two fingernails; it gives a characteristic snapping pop sound as the egg bursts. Children with nits on their hair have a 35–40% chance of also being infested with living lice and eggs. If lice are detected, the entire family needs to be checked (especially children up to the age of 13 years) with a louse comb, and only those who are infested with living lice should be treated. As long as no living lice are detected, the child should be considered negative for head louse infestation. Accordingly, a child should be treated with a pediculicide only when living lice are detected on their hair (not because he/she has louse eggs/nits on the hair and not because the scalp is itchy).

Body lice frequently lay their eggs on or near the seams of clothing. They must feed on blood and usually only move to the skin to feed. They exist worldwide and infest people of all races and can therefore spread rapidly under crowded living conditions where hygiene is poor (homeless, refugees, victims of war or natural disasters).

Symptoms of early scabies infestation mirror other skin diseases, including dermatitis, syphilis, erythema multiforme, various urticaria-related syndromes, allergic reactions, ringworm-related diseases, and other ectoparasites such as lice and fleas.

Scabies is endemic in many developing countries, where it tends to be particularly problematic in rural and remote areas. In such settings, community-wide control strategies are required to reduce the rate of disease, as treatment of only individuals is ineffective due to the high rate of reinfection. Large-scale mass drug administration strategies may be required where coordinated interventions aim to treat whole communities in one concerted effort. Although such strategies have shown to be able to reduce the burden of scabies in these kinds of communities, debate remains about the best strategy to adopt, including the choice of drug.

The resources required to implement such large-scale interventions in a cost-effective and sustainable way are significant. Furthermore, since endemic scabies is largely restricted to poor and remote areas, it is a public health issue that has not attracted much attention from policy makers and international donors.

A body lice infestation is treated by improving the personal hygiene of the infested person, including assuring a regular (at least weekly) change of clean clothes. Clothing, bedding, and towels used by the infested person should be laundered using hot water (at least ) and machine dried using the hot cycle.

Sometimes the infested person also is treated with a pediculicide (a medicine that can kill lice); however, a pediculicide generally is not necessary if hygiene is maintained and items are laundered appropriately at least once a week. A pediculicide should be applied exactly as directed on the bottle or by a physician.

Delousing can also be practically achieved by boiling all clothes and bedding, or washing them at a high temperature. A temperature of for 5 minutes will kill most of the adults and prevent eggs from hatching. Leaving the clothes unwashed, but unworn for a full week, also results in the death of lice and eggs.

Where this is not practical or possible, powder dusting with 10% DDT, 1% malathion or 1% permethrin is also effective.

Oral ivermectin at a dose of 12 mg on days 0, 7 and 14 has been used in a small trial of 33 people in Marseilles, but did not result in complete eradication, although there was a significant fall in the number of parasites and proportion of people infected. At the moment, ivermectin cannot be routinely recommended for the treatment of body lice.

Medication, insecticide or burning of clothing and bedding is usually not necessary, as the problem normally goes away with daily bathing, weekly (or more frequent) laundering and drying of clothing, bedding, towels, etc. in a hot clothes drier.

A definitive diagnosis of health effects due to bed bugs requires a search for and finding of the insect in the sleeping environment as symptoms are not sufficiently specific. Other possible conditions with which these conditions can be confused include scabies, allergic reactions, mosquito bites, spider bites, chicken pox and bacterial skin infections. Bed bugs classically form a line of bites colloquially referred to as "breakfast, lunch, and dinner" and rarely feed in the armpit or behind the knee which may help differentiate it from other biting insects. If the number in a house is large a pungent sweet odor may be described.

The number of diagnosed cases of human louse infestations (or pediculosis) has increased worldwide since the mid-1960s, reaching hundreds of millions annually. There is no product or method which assures 100% destruction of the eggs and hatched lice after a single treatment. However, there are a number of treatment methods that can be employed with varying degrees of success. These methods include chemical treatments, natural products, combs, shaving, hot air, silicone-based lotions, and ethanol (ethyl alcohol).

The pharmacological treatment of pediculosis include the use of crotamiton applied twice at 24 hour interval and washed off day after that. Benzyl benzoate also can be used when combined with lindane, it is applied once and then washed off after 24 hours.

Examination of the child's head at regular intervals using a louse comb allows the diagnosis of louse infestation at an early stage. Early diagnosis makes treatment easier and reduces the possibility of infesting others. In times and areas when louse infestations are common, weekly examinations of children, especially those 4–15 years old, carried out by their parents, will aid control. Additional examinations are necessary if the child came in contact with infested individuals, if the child frequently scratches his/her head, or if nits suddenly appear on the child's hair. Keeping long hair tidy could be helpful in the prevention of infestations with head lice.

Clothes, towels, bedding, combs, and brushes, which came in contact with the infested individual, can be disinfected either by leaving them outside for at least two days or by washing them at 60 °C (140 degrees F) for 30 minutes. This is because adult lice can survive only one to two days without a blood meal and are highly dependent on human body warmth. An insecticidal treatment of the house and furniture is not necessary.

Veterinarians usually attempt diagnosis with skin scrapings from multiple areas, which are then examined under a microscope for mites. "Sarcoptes" mites, because they may be present in relatively low numbers, and because they are often removed by dogs chewing at themselves, may be difficult to demonstrate. As a result, diagnosis in sarcoptic mange is often based on symptoms rather than actual confirmation of the presence of mites. A common and simple way of determining if a dog has mange is if it displays what is called a "pedal-pinna reflex", which is when the dog moves one of its hind legs in a scratching motion as the ear is being manipulated and scratched gently by the examiner; because the mites proliferate on the ear margins in nearly all cases at some point, this method works over 95% of the time. It is helpful in cases where all symptoms of mange are present but no mites are observed with a microscope. The test is also positive in animals with ear mites, an ear canal infection caused by a different but closely related mite (treatment is often the same). In some countries, an available serologic test may be useful in diagnosis.

Cattle infested with bovine pediculosis are generally treated chemically, by drugs like ivermectin and cypermethrin.

There are no diagnostic tests for tungiasis. This is most likely because the parasite is ectoparasitic with visible symptoms. Identification of the parasite through removal, and a patient’s traveling history, should suffice for diagnosis, though the latter is clearly more useful than the former. Localization of the lesion may be a useful diagnostic method for the clinician. A biopsy may be done, though again, it is not required for diagnosis.

A pubic louse infestation is usually diagnosed by carefully examining pubic hair for nits, nymphs, and adult lice. Lice and nits can be removed either with forceps or by cutting the infested hair with scissors (with the exception of an infestation of the eye area). A magnifying glass or a stereo-microscope can be used for identification.

Testing for other sexually transmitted infections is recommended in those who are infested with pubic lice.

Medical doctors and dermatologists can still misdiagnose this rash as many are unfamiliar with parasitism, not trained in it, or if they do consider it, cannot see the mites.

Different methods for detection are recognized for different acariasis infections. Human acariasis with mites can occur in the gastrointestinal tract, lungs, urinary tracts and other organs which not have been well-studied. For intestinal acariasis with symptoms such as abdominal pain, diarrhea, and phohemefecia (is this hemafecia?), human acariasis is diagnosed by detection of mites in stools. For pulmonary acariasis, the presence of mites in sputum is determined by identifying the presence and number of mites in the sputum of patients with respiratory symptoms. Both physical and chemical methods for liquefaction of sputum have been developed.

German entomologist Fritz Zumpt describes myiasis as "the infestation of live human and vertebrate animals with dipterous larvae, which at least for a period, feed on the host's dead or living tissue, liquid body substances, or ingested food". For modern purposes however, this is too vague. For example, feeding on dead or necrotic tissue is not generally a problem except when larvae such as those of flies in the family Piophilidae attack stored food such as cheese or preserved meats; such activity suggests saprophagy rather than parasitism; it even may be medically beneficial in maggot debridement therapy (MDT).

Currently myiasis commonly is classified according to aspects relevant to the case in question:

- The classical description of myiasis is according to the part of the host that is infected. This is the classification used by ICD-10. For example:

- dermal

- sub-dermal

- cutaneous (B87.0)

- creeping, where larvae burrow through or under the skin

- furuncular, where a larva remains in one spot, causing a boil-like lesion

- nasopharyngeal, in the nose, sinuses or pharynx (B87.3)

- ophthalmic or ocular, in or about the eye (B87.2)

- auricular, in or about the ear

- gastric, rectal, or intestinal/enteric for the appropriate part of the digestive system (B87.8)

- urogenital (B87.8)

- Another aspect is the relationship between the host and the parasite and provides insight into the biology of the fly species causing the myiasis and its likely effect. Thus the myiasis is described as either:

- obligatory, where the parasite cannot complete its life cycle without its parasitic phase, which may be specific, semispecific, or opportunistic

- facultative, incidental, or accidental, where it is not essential to the life cycle of the parasite; perhaps a normally free-living larva accidentally gained entrance to the host

Accidental myiasis commonly is enteric, resulting from swallowing eggs or larvae with one's food. The effect is called "pseudomyiasis". One traditional cause of pseudomyiasis was the eating of maggots of cheese flies in cheeses such as Stilton. Depending on the species present in the gut, pseudomyiasis may cause significant medical symptoms, but it is likely that most cases pass unnoticed.

Affected dogs need to be isolated from other dogs and their bedding, and places they have occupied must be thoroughly cleaned. Other dogs in contact with a diagnosed case should be evaluated and treated. A number of parasitical treatments are useful in treating canine scabies. Sulfurated lime (a mixture of calcium polysulfides) rinses applied weekly or biweekly are effective (the concentrated form for use on plants as a fungicide must be diluted 1:16 or 1:32 for use on animal skin).

Selamectin is licensed for treatment in dogs by veterinary prescription in several countries; it is applied as a dose directly to the skin, once per month (the drug does not wash off). A related and older drug ivermectin is also effective and can be given by mouth for two to four weekly treatments or until two negative skin scrapings are achieved. Oral ivermectin is not safe to use on some collie-like herding dogs, however, due to possible homozygous MDR1 (P-glycoprotein) mutations that increase its toxicity by allowing it into the brain. Ivermectin injections are also effective and given in either weekly or every two weeks in one to four doses, although the same MDR1 dog restrictions apply.

Affected cats can be treated with fipronil and milbemycin oxime.

Topical 0.01% ivermectin in oil (Acarexx) has been reported to be effective in humans, and all mite infections in many types of animals (especially in ear mite infections where the animal cannot lick the treated area), and is so poorly absorbed that systemic toxicity is less likely in these sites. Nevertheless, topical ivermectin has not been well enough tested to be approved for this use in dogs, and is theoretically much more dangerous in zones where the animal can potentially lick the treated area. Selamectin applied to the skin (topically) has some of the same theoretical problems in collies and MDR1 dogs as ivermectin, but it has nevertheless been approved for use for all dogs provided that the animal can be observed for 8 hours after the first monthly treatment. Topical permethrin is also effective in both dogs and humans, but is toxic to cats.

Afoxolaner (oral treatment with a chewable tablet containing afoxolaner 2.27% w/w) has been shown to be efficient against both sarcoptic and demodectic mange in dogs.

Sarcoptic mange is transmissible to humans who come into prolonged contact with infested animals, and is distinguished from human scabies by its distribution on skin surfaces covered by clothing. For treatment of sarcoptic infection in humans, see scabies. For demodetic infection in humans, which is not as severe as it is in animals with thicker coats (such as dogs), see "Demodex folliculorum".

Sparganosis is typically diagnosed following surgical removal of the worms, although the infection may also be diagnosed by identification of eosinophilia or identification of the parasite in a tissue specimen. If such biopsy and excision procedures are not feasible, the antisparganum ELISA test may be used. In theory, a pre-operative diagnosis could be made by identification of exposure history and a painful, migratory, subcutaneous nodule. Sparganosis usually presents as a single nodule, while other cestode infections such as cysticercosis typically present as multiple nodules. Preoperative diagnosis, however, is rare.

CT and MRI scans are especially useful for diagnosis of cerebral sparganosis, as they reveal lesions in the brain. Through a retrospective analysis of 25 cases of cerebral sparganosis from 2000 to 2006, Song et al. found a number of characteristic signs that could be used in the future to diagnose cerebral sparganosis without performing an excision or tissue biopsy. The most characteristic finding was the "tunnel sign" on MRI images, showing the migrating track of the worm, while the most common finding was multiple conglomerated ring-shaped enhancements, seen as bead-shaped, usually with 3 to 6 rings. These findings led Song et al. to suggest that clinical history, ELISA, and either MRI or CT scans could be sufficient to make a sparganosis diagnosis. These lesions, however, are sometimes mistaken for tuberculosis lesions. In one case cerebral sparganosis was not diagnosed for four years, during which scans showed a cluster of rings moving from the right to the left side of the brain; ultimately the worm was found on biopsy.

Treatment requires keeping the person from being repeatedly bitten and possible symptomatic use of antihistamines and corticosteroids (either topically or systemically). There however is no evidence that medications improve outcomes and symptoms usually resolve without treatment in 1–2 weeks.

Avoiding repeated bites can be difficult, since it usually requires eradicating bed bugs from a home or workplace; eradication frequently requires a combination of pesticide and non pesticide approaches. Pesticides that have historically been found to be effective include pyrethroids, dichlorvos and malathion. Resistance to pesticides has increased significantly over time and there are concerns of negative health effects from their usage. Mechanical approaches such as vacuuming up the insects and heat treating or wrapping mattresses have been recommended.

Ear mites of dogs and cats can be treated with any of the spot-on preparations available from veterinary surgeons as well as over the counter at many pet stores and online. If the chosen solution does not destroy mite eggs, treatment should be repeated after one month, to catch the next generation of mites that will have hatched by then. Relief, in terms of the cat or dog no longer scratching at his or her ears, will be noticeable within a few hours. However, since mite irritation is partly allergic (see scabies), symptoms may also outlive mites by weeks. Moreover, it may take topical antibiotics and several weeks to clear infected external wounds caused by scratching on the exterior surfaces of cat and dog ears.

Common home remedy treatment options include household ingredients such as isopropyl alcohol, acetic acid (vinegar), boric acid, tea tree oil, coconut oil, and many other plant based extracts, in varying proportions.

Option for treating ear mites in rabbits are the related antiparasitics ivermectin and selamectin. Both of these antiparasitics have also been used with good effect in cats and dogs. A topical preparation of 0.01% ivermectin (Acarexx) can be used directly as an oil in cat ears, and the related new generation drug selamectin (brand name "Revolution") is available as a once-per-month skin treatment for both dogs and cats, which will prevent new mite infestation as well as a number of other parasitic diseases. As with ivermectin, selamectin must be used with caution in collies and herder breeds with the possibility for homozygous MDR1 mutations. A single treatment with a topical formulation containing fipronil, (S)-methoprene, eprinomectin and praziquantel was shown to be efficient for the prevention of "Otodectes cynotis" infestation in cats.

Advice often given includes:

- Avoid sharing clothing, sports equipment, towels, or sheets.

- Wash clothes in hot water with fungicidal soap after suspected exposure to ringworm.

- Avoid walking barefoot; instead wear appropriate protective shoes in locker rooms and sandals at the beach.

- Avoid touching pets with bald spots, as they are often carriers of the fungus.

If infested, animals should be removed from the flock and all wool in and around roughly a 1 cm or larger radius of the discoloured area clipped. The area is treated with insecticide to kill the maggots. Soothing cream can also be applied to skin grazes or lesions caused by the maggots. Clippings should be collected after removal and placed in a maggot-proof bag and left closed in the sun, to ensure that no other animal is infected.

Under most situations, infection is hard to recognize because the symptoms are mild or even absent. In humans and wild animals, infection is not easily identified. Especially the adult flukes, even if in large number, generally do not cause complications. There is not yet a standard diagnostic test. Therefore, manual diagnosis is done at many levels. Diagnosis basically relies on a combination of postmortem analyses, clinical signs displayed by the animals, and response to drenching. In heavy infection, symptoms are easily observed in sheep and cattle as they become severely anorexic or inefficiently digest food, and become unthrifty. Copious fetid diarrhea is an obvious indication, as the soiling of hind legs and tails with fluid feces are readily noticeable. Even though it not always the case, immature flukes can be identified from the fluid excrement. On rare occasions, eggs can be identified from stools of suspected animals. In developing countries diagnosis and prognosis is often hindered by multiple infections with other trematodes, such as "Fasciola hepatica" and schistosomes, because these flukes are given primary importance due to their pervasive nature.

no approved human vaccine exist against "Dermatophytosis". For horses, dogs and cats there is available an approved inactivated vaccine called "Insol Dermatophyton" (Boehringer Ingelheim) which provides time-limited protection against several trichophyton and microsporum fungal strains.

The first control method is preventive and aims to eradicate the adult flies before they can cause any damage and is called vector control. The second control method is the treatment once the infestation is present, and concerns the infected animals (including humans).

The principal control method of adult populations of myiasis inducing flies involves insecticide applications in the environment where the target livestock is kept. Organophosphorus or organochlorine compounds may be used, usually in a spraying formulation. One alternative prevention method is the sterile insect technique (SIT) where a significant number of artificially reared sterilized (usually through irradiation) male flies are introduced. The male flies compete with wild breed males for females in order to copulate and thus cause females to lay batches of unfertilized eggs which cannot develop into the larval stage.

One prevention method involves removing the environment most favourable to the flies, such as by removal of the tail. Another example is the crutching of sheep, which involves the removal of wool from around the tail and between the rear legs, which is a favourable environment for the larvae. Another, more permanent, practice which is used in some countries is mulesing, where skin is removed from young animals to tighten remaining skin – leaving it less prone to fly attack.

To prevent myiasis in humans, there is a need for general improvement of sanitation, personal hygiene, and extermination of the flies by insecticides. Clothes should be washed thoroughly, preferably in hot water, dried away from flies, and ironed thoroughly. The heat of the iron kills the eggs of myiasis-causing flies.

Both over-the-counter and prescription medications are available for treatment of pubic lice infestations. A lice-killing lotion containing 1% permethrin or a mousse containing pyrethrins and piperonyl butoxide can be used to treat pubic ("crab") lice. These products are available over-the-counter without a prescription at a local drug store or pharmacy. These medications are safe and effective when used exactly according to the instructions in the package or on the label. Effectiveness of treatment is increased when the pediculicide is left on the skin and hair for at least an hour A second round of treatment is recommended within the following seven to ten days to kill newly hatched nymphs. Lindane is a second line treatment due to concerns of toxicity. The Centers for Disease Control and Prevention (CDC) states that lindane should not be used by persons who have extensive dermatitis, women who are pregnant or lactating or children aged under two years. The FDA similarly warns against use in patients with a history of uncontrolled seizure disorders and cautious use in infants, children, the elderly, and individuals with other skin conditions (e.g., atopic dermatitis, psoriasis) and in those who weigh less than 110 lbs (50 kg).

Bedding and clothing is laundered and sexual contact should be avoided until no signs of infestation exists. A second treatment is occasionally required if not improved after 3 to 7 days.

Pubic lice are primarily spread through sexual intercourse. Therefore, all partners with whom the patient has had sexual contact within the previous 30 days should be evaluated and treated, and sexual contact should be avoided until all partners have successfully completed treatment and are thought to be cured. Because of the strong association between the presence of pubic lice and classic sexually transmitted infections (STIs), patients may be diagnosed with other STIs.

Because the crab louse needs hair to attach its eggs to, shaving the pubic area denies them this opportunity and should be enough to eliminate an infestation. However, the eyelids should be checked as well and treated accordingly.

Infections of the eyelashes may be treated with either petroleum jelly applied twice daily for 10 days or malathion, phenothrin, and carbaryl.

Metagonimiasis is diagnosed by eggs seen in feces. Only after antihelminthic treatment will adult worms be seen in the feces, and then can be used as part of a diagnostic procedure. A 1993 analysis of the efficacy of ELISA tests to diagnose metagonimiasis implied that simultaneous screening of specific antibodies to several parasite agents are important in serological diagnosis of acute parasitic disease and more research should be done on the efficacy of these methods of diagnosis.

Diagnosis may be difficult because the egg-laying capacity of heterophyids is limited, and therefore sedimentation concentration procedures may be needed to demonstrate eggs in lighter infections. Accurate species identification is also difficult because eggs of most flukes are similar in size and morphology, especially those of "Heterophyes heterophyes", "Clonorchis" and "Opisthorchis". It is important to ask where the person may have contracted the disease, find out if they have been to en endemic area, and check for signs and symptoms that would lead to metagonimiasis.