Drug and alcohol use can contribute to pruritus as well so it is worthwhile to gather a social history. Those who use cocaine and amphetamines may experience pruritus due to feelings of abnormal cutaneous sensations called delusions of parasitosis, also known as "meth mites". Opioid users can also experience pruritus so examining a patients medication list can be beneficial. Diagnostic criteria
The French Psychodermatology Group is a subgroup of the French Society of Dermatology made up on psychiatrists, dermatologists and psychologists. They met in 2007 to propose diagnostic criteria for this disease in hope of preventing further misdiagnosis of this condition. They believed the term "functional itch disorder" was the best phrase to describe this condition, avoiding the use of the word "psychogenic". To diagnose a patient with functional itch disorder, the patient should meet three required criteria and three of seven optional criteria.Diagnostic Criteria:
3 Required criteria
Localized or generalized pruritus without a primary skin lesion
Chronic pruritus, characterized as being greater than 6 weeks
There is no somatic cause present
7 Optional criteria (need 3 to diagnose)
A chronological relationship of pruritus with one or several life events that can have psychological consequences
Changes during the nighttime
More present during rest or inaction
There is a coupled psychological disorder
Pruritus that could be improved with pyschotropic drugs
Pruritus that could be improved by psychotherapies

Treatment
The treatment for this condition has not been well studied but the most common options are psychotherapy and medicines geared toward psychiatric conditions. Stress reduction and relaxation techniques have also been shown to be helpful for alleviating this condition.
Ectodermal dysplasia (ED) is a group of genetic syndromes all deriving from abnormalities of the ectodermal structures. : 570  More than 150 different syndromes have been identified.Despite some of the syndromes having different genetic causes, the symptoms are sometimes very similar. Diagnosis is usually by clinical observation, often with the assistance of family medical histories so that it can be determined whether transmission is autosomal dominant or recessive. Ectodermal dysplasias are described as "heritable conditions in which there are abnormalities of two or more ectodermal structures such as the hair, teeth, nails, sweat glands, salivary glands, cranial-facial structure, digits and other parts of the body." Presentation
Hair
Individuals affected by an ED syndrome frequently have abnormalities of the hair follicles. Scalp and body hair may be thin, sparse, and very light in color, even though beard growth in affected males may be normal. The hair may grow very slowly or sporadically and it may be excessively fragile, curly, or even twisted. Kinky hair is also a possibility. Nails
Fingernails and toenails may be thick, abnormally shaped, discolored, ridged, slow-growing, or brittle. The cuticles may be prone to infections. Skin
The skin may be lightly pigmented. Skin sustaining injury may grow back permanently hypo-pigmented. In some cases, red or brown pigmentation may be present. Skin can be prone to rashes or infections and can be thick over the palms and soles. Care must be taken to prevent cracking, bleeding, and infection. Sweat glands
Individuals affected by certain ED syndromes cannot perspire.