Some people earnestly believe that they are actively infested, even though no louse or other parasite can be detected. These cases can be particularly difficult to investigate and to manage. The affected individual should not be dismissed as being mentally unstable. Every reasonable effort should be explored to identify the cause of the sensations / irritation, bite-like reactions / lesions, and to capture and identify any offending creature on the scalp or body. The irritant may, indeed, be a louse or some other type of biting insect or mite, but may not necessarily be infesting the person at the time of examination. Diverse insects (e.g. mosquitoes, fleas, bed bugs) may only transiently visit a person, and these may not be noticed in the act of biting. Certain blood-feeding mites associated with birds and rodents may be present in a home and cause annoyance when they feed upon a person. Itching and irritation in some cases may also be ascribed to hair care and laundry products, industrial fibers, underlying disease, or even to pediculicidal (anti-louse) treatments and yet other kinds of drugs. The clinician will often find it valuable to consult with an entomologist on these matters. To learn more about our identification services, visit the section of our website on Specimen Evaluation.
A few people remain convinced that their infestation is real, even though they have been examined by one or more competent specialists who can find no physical cause for their discomfort. The condition is variously referred to as delusional-, delusory- or illusory-parasitosis, ‘Morgellons syndrome’ and Ekbom Syndrome. Based upon a recent thorough clinical review of 115 sufferers of “Morgellons syndrome”, none of these patients had a demonstrable parasite. Instead offending materials collected from the skin were composed mainly of cotton fibers, most likely from clothing or linens that had become adherent to existing lesions. Interesting, more than half of the patients manifested with a cognitive impairment, and a psycho-active drug was detected in hair samples of half of the patients.
Some patients may pose a danger to themselves and others by resorting to the use of toxic or flammable substances in attempts to rid themselves of their real or perceived infestation. Such a person may, indeed, be delusional, but should be treated with care and respect when referred for counseling. Certain people develop an extreme phobia or irrational fear that they will acquire lice or other parasites from virtually any animate or inanimate object. Patients who are unduly burdened by this condition are likely to benefit from counseling with a clinician specializing in phobias and obsessive-compulsive disorders. Readers are advised to exercise great care and healthy skepticism when reading blogs and other Internet resources about such matters.