Delusional parasitosis (DP) is a mental disorder in which individuals have a persistent belief that they are infested with living or nonliving pathogens such as parasites, insects, or bugs, when no such infestation is present. They usually report tactile hallucinations known as formication, a sensation resembling insects crawling on or under the skin. Morgellons is considered to be a subtype of this condition, in which individuals have sores that they believe contain harmful fibers.
Lichen simplex chronicus (LSC) is thick leathery skin with exaggerated skin markings caused by sudden itching and excessive rubbing and scratching. It generally results in small bumps, patches, scratch marks and scale. It typically affects the neck, scalp, upper eyelids, ears, palms, soles, ankles, wrists, genital areas and bottom. It often develops gradually and the scratching becomes a habit.
Itch is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response patterns are different. Pain creates a withdrawal reflex, whereas itches leads to a scratch reflex.
Antipruritics, abirritants, or anti-itch drugs, are medications that inhibit the itching often associated with sunburns, allergic reactions, eczema, psoriasis, chickenpox, fungal infections, insect bites and stings like those from mosquitoes, fleas, and mites, and contact dermatitis and urticaria caused by plants such as poison ivy or stinging nettle. It can also be caused by chronic kidney disease and related conditions.
A diagnosis of exclusion or by exclusion is a diagnosis of a medical condition reached by a process of elimination, which may be necessary if presence cannot be established with complete confidence from history, examination or testing. Such elimination of other reasonable possibilities is a major component in performing a differential diagnosis.
Aquagenic pruritus is a skin condition characterized by the development of severe, intense, prickling-like epidermal itching without observable skin lesions and evoked by contact with water.
Stiff-person syndrome (SPS), also known as stiff-man syndrome, is a rare neurological disorder of unclear cause characterized by progressive muscular rigidity and stiffness. The stiffness primarily affects the truncal muscles and is characterised by spasms, resulting in postural deformities. Chronic pain, impaired mobility, and lumbar hyperlordosis are common symptoms.
Pruritic urticarial papules and plaques of pregnancy (PUPPP), known in United Kingdom as polymorphic eruption of pregnancy (PEP), is a chronic hives-like rash that strikes some women during pregnancy. Some skin changes are known to occur in people who are pregnant while other skin conditions, or dermatoses, that people have prior to getting pregnant will become altered or symptoms will increase. Pruritic urticarial papules and plaques of pregnancy (PUPPP) is one of many skin conditions that is specific to pregnancy and occurs in about 1 in every 160 (0.625%) of pregnancies.
Prurigo nodularis (PN), also known as nodular prurigo, is a skin disorder characterized by pruritic (itchy), nodular lesions, which commonly appear on the trunk, arms and legs. Patients often present with multiple excoriated nodules caused by chronic scratching. Although the exact cause of PN is unknown, PN is associated with other dermatologic conditions such as untreated or severe atopic dermatitis and systemic causes of pruritus including liver disease and end stage kidney disease. The goal of treatment in PN is to decrease itching. PN is also known as Hyde prurigo nodularis, or Picker's nodules.
Psychodermatology is the treatment of skin disorders using psychological and psychiatric techniques by addressing the interaction between mind and skin. Though historically there has not been strong scientific support for its practice, there is increasing evidence that behavioral treatments may be effective in the management of chronic skin disorders.
Pruritus ani is the irritation of the skin at the exit of the rectum, known as the anus, causing the desire to scratch. The intensity of anal itching increases from moisture, pressure, and rubbing caused by clothing and sitting. At worst, anal itching causes intolerable discomfort that often is accompanied by burning and soreness. It is estimated that up to 5% of the population of the United States experiences this type of discomfort daily.
Basophilia is the condition of having greater than 200 basophils/μL in the venous blood. Basophils are the least numerous of the myelogenous cells, and it is rare for their numbers to be abnormally high without changes to other blood components. Rather, basophilia is most often coupled with other white blood cell conditions such as eosinophilia, high levels of eosinophils in the blood. Basophils are easily identifiable by a blue coloration of the granules within each cell, marking them as granulocytes, in addition to segmented nuclei.
Schamberg's disease, is a chronic discoloration of the skin found in people of all ages, usually only affecting the feet, legs or thighs or a combination. It may occur as a single event or subsequent bouts may cause further spread. It is most common in males. It is named after Jay Frank Schamberg, who described it in 1901. There is no known cure for this disease but it is not a life-threatening condition and is mainly of cosmetic concern, although, because it can appear so suddenly, so extensively and because it usually leaves permanent discoloration of the skin, it can cause understandable psychological concern. The skin lesions sometimes cause itching, which can be treated by applying cortisone cream. The cortisone cream will only help with the itching and does not improve the discoloration of the skin. Schamberg's disease causes no other symptoms beside skin discoloration and itching. The condition is caused by inflammation of capillaries near the surface of skin and subsequent leaking of red blood cells into surrounding tissues. As the red blood cells break down and get mostly resorbed, some of the iron released by the red blood cells remains in the skin and causes the characteristic rust-colored appearance. The cause of the capillary inflammation is usually unknown.
Notalgia paresthetica or Notalgia paraesthetica (NP) (also known as "Hereditary localized pruritus", "Posterior pigmented pruritic patch", and "subscapular pruritus") is a chronic sensory neuropathy. Notalgia paresthetica is a common localized itch, affecting mainly the area between the shoulder blades (especially the T2–T6 dermatomes) but occasionally with a more widespread distribution, involving the shoulders, back, and upper chest. The characteristic symptom is pruritus (itch or sensation that makes a person want to scratch) on the back, usually on the left hand side below the shoulder blade (mid to upper back). It is occasionally accompanied by pain, paresthesia (pins and needles), or hyperesthesia (unusual or pathologically increased sensitivity of the skin to sensory stimuli, such as pain, heat, cold, or touch), which results in a well circumscribed hyperpigmentation of a skin patch in the affected area.
Schnitzler syndrome or Schnitzler's syndrome is a rare disease characterised by onset around middle age of chronic hives (urticaria) and periodic fever, bone pain and joint pain, weight loss, malaise, fatigue, swollen lymph glands and enlarged spleen and liver.
Brachioradial pruritus is an intense itching sensation of the arm usually between the wrist and elbow of either or both arms. The itch can be so intense that affected individuals will scratch their own skin to a bleeding condition.
Uremic pruritus is caused by chronic kidney failure and is the most common internal systemic cause of itching.
Morgellons is the informal name of a self-diagnosed, scientifically unsubstantiated skin condition in which individuals have sores that they believe contain fibrous material. Morgellons is not well understood, but the general medical consensus is that it is a form of delusional parasitosis, on the psychiatric spectrum. The sores are typically the result of compulsive scratching, and the fibers, when analysed, are consistently found to have originated from cotton and other textiles.
Cholestatic pruritus is the sensation of itch due to nearly any liver disease, but the most commonly associated entities are primary biliary cholangitis, primary sclerosing cholangitis, obstructive choledocholithiasis, carcinoma of the bile duct, cholestasis, and chronic hepatitis C viral infection and other forms of viral hepatitis.
Senile pruritus is one of the most common conditions in the elderly or people over 65 years of age with an emerging itch that may be accompanied with changes in temperature and textural characteristics. In the elderly, xerosis, is the most common cause for an itch due to the degradation of the skin barrier over time. However, the cause of senile pruritus is not clearly known. Diagnosis is based on an elimination criteria during a full body examination that can be done by either a dermatologist or non-dermatologist physician.
