Shwartzman phenomenon, also known as Shwartzman reaction, is a rare reaction of a body to particular types of toxins, called endotoxins, which cause thrombosis in the affected tissue. A clearing of the thrombosis results in a reticuloendothelial blockade, which prevents re-clearing of the thrombosis caused by a repeat introduction of the toxin. That will cause tissue necrosis. Shwartzman phenomenon is usually observed during delivery or abortion, when foreign bodies are introduced into the tissues of the female reproductive system.

The Shwartzman phenomenon is named for Gregory Shwartzman, the doctor at Mount Sinai Hospital in New York City who was the first to develop the concept of immune system hypersensitivity in the 1920s.

This reaction was experimented using "Neisseria meningitidis" endotoxin.

This is notably seen with "Neisseria meningitidis".

This condition is characterized by:

- a diffuse infiltration of all the skin which never transforms into nodule

- a complete alopecia of eyebrows and eyelashes and body hair

- an anhydrotic and dysesthesic zones of the skin

- a peculiar type of lepra reaction named Lucio's phenomenon or necrotic erythema

Lucio's phenomenon consists of well-shaped erythematous spots which later become necrotic with scabs, ulcerations and scars. These lesion usually on the lower extremities and may be extensive They are frequently painful. Rarely it may be fatal.

Raynaud's phenomenon is frequently the first manifestation of CREST/lcSSc, preceding other symptoms by years. Stress and cold temperature induce an exaggerated vasoconstriction of the small arteries, arterioles, and thermoregulatory vessels of the skin of the digits. Clinically this manifests as a white-blue-red transitions in skin color. Underlying this transition is pallor and cyanosis of the digits, followed by a reactive hyperemia as they rewarm. When extreme and frequent, this phenomenon can lead to digital ulcerations, gangrene, or amputation.

Ulceration can predispose to chronic infections of the involved site.

Presents as a sensation of food getting stuck (dysphagia) in the mid- or lower esophagus, atypical chest pain, or cough. Patients often state they must drink liquids to swallow solid food. This motility problem results from atrophy of the gastrointestinal tract wall smooth muscle. This change may occur with or without pathologic evidence of significant tissue fibrosis.

Reynolds syndrome is a rare secondary laminopathy, consisting of the combination of primary biliary cirrhosis and progressive systemic sclerosis. In some patients this syndrome has also been associated with Sjögren's syndrome and hemolytic anemia. Typical clinical features include jaundice, elevated blood levels of alkaline phosphatase, calcinosis cutis, telangiectasias, and pruritus. This disease may cause white or yellow-ish spots on the arms or legs. The syndrome, a special case of scleroderma, is named after the American physician, Telfer B. Reynolds, MD (1921–2004), who first described it. He is also known for creating one of the world's first hepatology programs at the University of Southern California.

It should not be confused with the more common Raynaud's phenomenon.

The diffuse leprosy of Lucio and Latapí, also known as diffuse lepromatous leprosy or "pretty leprosy" is a clinical variety of lepromatous leprosy. It was first described by Lucio and Alvarado in 1852 and re-identified by Latapí in 1936. It is common in Mexico (23% leprosy cases) and in Costa Rica and very rare in other countries.

Although a clear understanding of the various skin lesions in IgG4-related disease is a work in progress, skin lesions have been classified into subtypes based on documented cases:

- Angiolymphoid hyperplasia with eosinophilia (or lesions that mimic it) and cutaneous pseudolymphoma

- Cutaneous plasmacytosis

- Eyelid swelling (as part of Mikulicz's disease)

- Psoriasis-like eruptions

- Unspecified maculopapular or erythematous eruptions

- Hypergammaglobulinemic purpura and urticarial vasculitis

- Impaired blood supply to fingers or toes, leading to Raynaud's phenomenon or gangrene

Note:

In addition, Wells syndrome has also been reported in a case of IgG4-related disease.

Symptoms vary but they mostly involve skin disorders. The signs to look for include Raynaud's phenomenon, arthritis, myositis and scleroderma.

Visual symptoms include discoloring of the skin and painful swelling.

Mees' lines appear after an episode of poisoning with arsenic, thallium or other heavy metals, and can also appear if the subject is suffering from renal failure. They have been observed in chemotherapy patients.

They are typically white bands traversing the width of the nail. As the nail grows they move towards the end, and finally disappear when trimmed.

Scleromyositis or the PM/Scl overlap syndrome is a complex autoimmune disease (a disease in which the immune system attacks the body). Patients with scleromyositis have symptoms of both systemic scleroderma and either polymyositis or dermatomyositis, and is therefore considered an overlap syndrome. Although it is a rare disease, it is one of the more common overlap syndromes seen in scleroderma patients, together with MCTD and Antisynthetase syndrome. Autoantibodies often found in these patients are the anti-PM/Scl (anti-exosome) antibodies.

The symptoms that are seen most often are typical symptoms of the individual autoimmune diseases and include Raynaud's phenomenon, arthritis, myositis and scleroderma. Treatment of these patients is therefore strongly dependent on the exact symptoms with which a patient reports to a physician and is similar to treatment for the individual autoimmune disease, often involving either immunosuppressive or immunomodulating drugs.

- Clinical characteristics:

- Overlap Syndrome: scleroderma overlap syndrome

- Autoimmune disease

- Scleroderma myositis overlap syndrome

The condition can cause pain within the affected extremities, discoloration (paleness), and sensations of cold and/or numbness. This can often be distressing to those who are undiagnosed, and sometimes it can be obstructive. If someone with Raynaud's is placed into a cold climate, it could potentially become dangerous.

1. When exposed to cold temperatures, the blood supply to the fingers or toes, and in some cases the nose or earlobes, is markedly reduced; the skin turns pale or white (called pallor) and becomes cold and numb.

2. When the oxygen supply is depleted, the skin color turns blue (called cyanosis).

3. These events are episodic, and when the episode subsides or the area is warmed, the blood flow returns, and the skin color first turns red (rubor), and then back to normal, often accompanied by swelling, tingling, and a painful "pins and needles" sensation.

All three color changes are observed in classic Raynaud's. However, not all patients see all of the aforementioned color changes in all episodes, especially in milder cases of the condition. Symptoms are thought to be due to reactive hyperemias of the areas deprived of blood flow.

In pregnancy, this sign normally disappears owing to increased surface blood flow. Raynaud's has also occurred in breastfeeding mothers, causing nipples to turn white and become extremely painful. Nifedipine, a calcium channel blocker and vasodilator, was recommended to increase blood flow to the extremities and noticeably relieved pain in the breast in an extremely small study group.

IgG4-related skin disease is the recommended name for skin manifestations in IgG4-related disease (IgG4-RD). Multiple different skin manifestations have been described.

This is rare and is usually due to mutations in the R-spondin 4 (RSPO4) gene which is located on the short arm of chromosome 20 (20p13). Clinically it is manifest by the absence (anonychia) or hypoplasia (hyponuchia) of finger- and/or toenails.

Anonychia is the absence of nails, an anomaly, which may be the result of a congenital ectodermal defect, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus, epidermolysis bullosa, or severe exfoliative diseases.

The Mazzotti reaction, first described in 1948, is a symptom complex seen in patients after undergoing treatment of onchocerciasis with the medication diethylcarbamazine (DEC). Mazzotti reactions can be life-threatening, and are characterized by fever, urticaria, swollen and tender lymph nodes, tachycardia, hypotension, arthralgias, oedema, and abdominal pain that occur within seven days of treatment of microfilariasis. The Mazzotti reaction correlates with intensity of infection; however, there are probably multiple infection intensity-dependent mechanisms responsible for mediating this complex reaction.

The phenomenon is so common when DEC is used for the treatment of onchocerciasis that this drug is the basis of a skin patch test used to confirm that diagnosis. The drug patch is placed on the skin, and if the patient is infected with the microfilaria of "O. volvulus", localized pruritus and urticaria are seen at the application site.

A case of the Mazzotti reaction has been reported after presumptive treatment of schistosomiasis and strongyloidiasis with ivermectin, praziquantel and albendazole. The patient had complete resolution of symptoms after intravenous therapy with methylprednisolone.

The symptoms experienced in cholesterol embolism depend largely on the organ involved. Non-specific symptoms often described are fever, muscle ache and weight loss. Embolism to the legs causes a mottled appearance and purple discoloration of the toes, small infarcts and areas of gangrene due to tissue death that usually appear black, and areas of the skin that assume a marbled pattern known as "livedo reticularis". The pain is usually severe and requires opiates. If the ulcerated plaque is below the renal arteries the manifestations appear in both lower extremities. Very rarely the ulcerated plaque is below the aortic bifurcation and those cases the changes occur only in one lower extremity.

Kidney involvement leads to the symptoms of renal failure, which are non-specific but usually cause nausea, reduced appetite (anorexia), raised blood pressure (hypertension), and occasionally the various symptoms of electrolyte disturbance such as an irregular heartbeat. Some patients report hematuria (bloody urine) but this may only be detectable on microscopic examination of the urine. Increased amounts of protein in the urine may cause edema (swelling) of the skin (a combination of symptoms known as nephrotic syndrome).

If emboli have spread to the digestive tract, reduced appetite, nausea and vomiting may occur, as well as nonspecific abdominal pain, gastrointestinal hemorrhage (vomiting blood, or admixture of blood in the stool), and occasionally acute pancreatitis (inflammation of the pancreas).

Both the central nervous system (brain and spinal cord) and the peripheral nervous system may be involved. Emboli to the brain may cause stroke-like episodes, headache and episodes of loss of vision in one eye (known as amaurosis fugax). Emboli to the eye can be seen by ophthalmoscopy and are known as plaques of Hollenhorst. Emboli to the spinal cord may cause paraparesis (decreased power in the legs) or cauda equina syndrome, a group of symptoms due to loss of function of the distal part of the spinal cord - loss of control over the bladder, rectum and skin sensation around the anus. If the blood supply to a single nerve is interrupted by an embolus, the result is loss of function in the muscles supplied by that nerve; this phenomenon is called a "mononeuropathy".

Raynaud syndrome, also known as Raynaud's phenomenon, is a medical condition in which spasm of arteries cause episodes of reduced blood flow. Typically the fingers, and less commonly the toes, are involved. Rarely, the nose, ears, or lips are affected. The episodes result in the affected part turning white and then blue. Often, there is numbness or pain. As blood flow returns, the area turns red and burns. The episodes typically last minutes, but can last up to several hours.

Episodes are often triggered by cold or emotional stress. There are two main types: primary Raynaud's, when the cause is unknown, and secondary Raynaud's, which occurs as a result of another condition. Secondary Raynaud's can occur due to a connective tissue disorder, such as scleroderma or lupus, injuries to the hands, smoking, thyroid problems, and certain medications, such as birth control pills. Diagnosis is typically based on the symptoms.

The primary treatment is avoiding the cold. Other measures include the discontinuation of nicotine or stimulants use. Medications for treatment of cases that do not improve include calcium channel blockers and iloprost. Little evidence supports alternative medicine. Severe disease may rarely be complicated by skin sores or gangrene.

About 4% of people have the condition. Onset of the primary form is typically between ages 15 and 30 and occurs more frequently in females. The secondary form usually affects older people. Both forms are more common in cold climates. It is named after the French physician Maurice Raynaud, who described the condition in 1862.

Sclerodactyly is a localized thickening and tightness of the skin of the fingers or toes. Sclerodactyly often leads to ulceration of the skin of the distal digits and is commonly accompanied by atrophy of the underlying soft tissues.

The term "sclerodactyly" is made up from the Greek "skleros" meaning hard and "daktylos" meaning a finger or toe – "hard fingers or toes".

It is sometimes associated with scleroderma and mixed connective tissue disease, auto-immune disorders.

Sclerodactyly is a component of the CREST variant of scleroderma (CREST is an acronym that stands for calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia.)

Uveoparotitis is a symptom of sarcoidosis. It describes a chronic inflammation of the parotid gland and uvea. There is also a phenomenon called Waldenström's uveoparotitis. In this case, the symptom is related to Heerfordt's syndrome.

When skin is blanched, it takes on a whitish appearance as blood flow to the region is prevented. This occurs during and is the basis of the physiologic test known as diascopy.

Blanching of the fingers is also one of the most clinically evident signs of Raynaud's phenomenon.

Blanching is prevented in gangrene as the red blood corpuscles are extravasated and impart red color to the gangrenous part.

Moist desquamation is a description of the clinical pattern seen as a consequence of radiation exposure where the skin thins and then begins to weep because of loss of integrity of the epithelial barrier and decreased oncotic pressure. Typically this occurs at doses of 15–20 Gray, far higher than any diagnostic scan and more typical of levels seen in radiotherapy or deployment of nuclear armament. Historically, this was a common phenomenon in Hiroshima and Nagasaki during World War II with the atomic bomb attacks from the United States.

The phenomenon was famously described by John Hersey in his article, and later book, Hiroshima.

Toxic abortion is a medical phenomenon of spontaneous abortion, miscarriage, or stillbirth caused by toxins in the environment of the mother during pregnancy, especially as caused by toxic environmental pollutants, though sometimes reported as caused by naturally occurring plant toxins.

The size of oral mucoceles vary from 1 mm to several centimeters and they usually are slightly transparent with a blue tinge. On palpation, mucoceles may appear fluctuant but can also be firm. Their duration lasts from days to years, and may have recurrent swelling with occasional rupturing of its contents.

Cholesterol embolism (often cholesterol crystal embolism or atheroembolism, sometimes blue toe or purple toe syndrome or trash foot or warfarin blue toe syndrome) occurs when cholesterol is released, usually from an atherosclerotic plaque, and travels as an embolus in the bloodstream to lodge (as an embolism) causing an obstruction in blood vessels further away. Most commonly this causes skin symptoms (usually livedo reticularis), gangrene of the extremities and sometimes renal failure; problems with other organs may arise, depending on the site at which the cholesterol crystals enter the bloodstream. When the kidneys are involved, the disease is referred to as atheroembolic renal disease (AERD). The diagnosis usually involves biopsy (removing a tissue sample) from an affected organ. Cholesterol embolism is treated by removing the cause and giving supportive therapy; statin drugs have been found to improve the prognosis.