Keratolytic Winter erythema ( Oudtshoorn disease and Oudtshoorn skin, }is a rare autosomal dominant skin disease of unknown cause which causes redness and peeling of the skin on the palms and soles. Onset, increased prominence and severity usually occurs during winter. It is a type of genodermatosis.

The name "Oudtshoorn skin" derives from the town of Oudtshoorn in the Western Cape province of South Africa, where the disorder was first described. It is one of several genetic disorders known to be highly prevalent among the Afrikaner population.

KWE is characterized by a number of anomalies affecting the skin. Erythema causes redness of the skin, which is generally associated with inflammation and irritation. Including erythema and hyperkeratosis (thickening of the stratum corneum), naturally occurring keratolytic peeling and scaling, with increased manifestation in winter, are prevailing features of the disorder.

Erythema in KWE has been attributed to necrobiosis (cellular death) within the malpighian layer (the innermost layer of the epidermis). Peeling and scaling are caused by spreading dissection of the stratum corneum, correlating to the underlying necrobiosis.

The effects of KWE appear intermittently as patches on the skin of the palms and soles, with these patches appearing on the limbs, buttocks and torso in severe cases. Facial lesions of this type have also been reported with the disorder, though this is considered to be an extremely rare occurrence.

Onset and cyclical recurrence of KWE have shown to be associated with the arrival of winter, or winter-like weather. Worsening of symptoms during this time may be considered as an indicator of recurrent onset in patients known to have the disorder, and age of initial onset can be from early childhood to young adulthood, with attenuation of symptoms sometimes happening after age 30. Patients first exhibiting the disorder at a younger age may also experience worsened symptoms. Currently, no specific correlating factor or reason for winter-related manifestation has been established, though the coldness and dryer air common to winter conditions may be suspect. Winter onset is, however, considered to be a distinguishing feature of KWE among other erythematic skin disorders.

When peeling of skin occurs, the newly exposed layer of skin underneath is moist, raw and very sensitive. While this may result in minor discomfort and inconvenience, in severe cases of KWE where large areas of raw skin are present, it is often life-altering and debilitating.

KWE is inherited in an autosomal dominant manner. This means that the defective gene responsible for the disorder is located on an autosome (chromosome 8 is an autosome), and one copy of the defective gene is sufficient to cause the disorder when inherited from a parent who also has the disorder.

KWE can begin as a spontaneous mutation, first appearing in an individual with no previous family history of the disorder. This may be due to a genetic predisposition for the disorder, possibly connected to the Oudtshoorn ancestral line.

The symptoms can occur anywhere between days to months after administration of the offending medication, depending on the dose and speed of administration (Baack and Burgdorf, 1991; Demirçay, 1997). The patient first experiences tingling and/or numbness of the palms and soles that evolves into painful, symmetric, and well-demarcated swelling and red plaques. This is followed by peeling of the skin and resolution of the symptoms (Apisarnthanarax and Duvic 2003).

Chemotherapy-induced acral erythema (also known as palmar-plantar erythrodysesthesia, palmoplantar erythrodysesthesia, or hand-foot syndrome) is reddening, swelling, numbness and desquamation (skin sloughing or peeling) on palms of the hands and soles of the feet (and, occasionally, on the knees, elbows, and elsewhere) that can occur after chemotherapy in patients with cancer. Hand-foot syndrome is also rarely seen in sickle-cell disease. These skin changes usually are well demarcated. Acral erythema typically disappears within a few weeks after discontinuation of the offending drug.

Gianotti–Crosti syndrome mainly affects infants and young children. Children as young as 1.5 months and up to 12 years of age are reported to be affected. It is generally recognized as a papular or papulovesicular skin rash occurring mainly on the face and distal aspects of the four limbs. Purpura is generally not seen but may develop upon tourniquet test. However, extensive purpura without any hemorrhagic disorder has been reported. The presence of less lesions on the trunk does not exclude the diagnosis. Lymphadenopathy and hepatomegaly are sometimes noted. Raised AST and ALT levels with no rise in conjugated and unconjugated bilirubin levels are sometimes detectable, although the absence of such does not exclude the diagnosis. Spontaneous disappearance of the rash usually occurs after 15 to 60 days.

Rowell's Syndrome was described by Professor Neville Rowell and colleagues in 1963. Patients with the syndrome have lupus erythematosus (discoid or systemic), annular lesions of the skin like erythema multiforme associated with a characteristic pattern of immunological abnormalities. It is uncommon but occurs worldwide.

Rowell's syndrome has been reported to occur with all subtypes of LE (systemic, acute, subacute or discoid).

Erythema gyratum repens (also known as "Gammel's disease") is a figurate erythema that is rapidly moving and usually a marker of underlying cancer, usually from the lung.

Occurring at any age these lesions appear as raised pink-red ring or bulls-eye marks. They range in size from . The lesions sometimes increase size and spread over time and may not be complete rings but irregular shapes. Distribution is usually on the thighs and legs but can also appear on the upper extremities, areas not exposed to sunlight, trunk or face. Currently EAC is not known to be contagious, but as many cases are incorrectly diagnosed as EAC, it is difficult to be certain.

It occurs in less than 5% of patients with rheumatic fever, but is considered a major Jones criterion when it does occur. The four other major criteria include carditis, polyarthritis, Sydenham's Chorea, and subcutaneous nodules. In this case, it is often associated with Group A streptococcal infection, otherwise known as "Streptococcus pyogenes" infection, which can be detected with an ASO titer.

It is an early feature of rheumatic fever and not pathognomonic of it. It may be associated with mild myocarditis (inflammation of heart muscle). It is also seen in conditions like allergic drug reactions, sepsis and glomerulonephritis.

It often occurs as a harbinger of attacks in hereditary angioedema. In this case it may occur several hours or up to a day before an attack.

Clinically, three distinct patterns of palmoplantar keratoderma may be identified: diffuse, focal, and punctate.

The burning heat is usually limited to the soles of the feet, but may extend up to the ankles or lower legs of some patients. The burning can sometimes be accompanied by feelings of 'pins and needles' or tingling in these regions. Nighttime is when almost all sufferers of this syndrome report the heat symptoms being the worst, with the condition getting better as morning comes. Those who have psychosomatic disorders sometimes display psychological symptoms along with the burning of feet associated with the syndrome. For most, there is no erythema of the skin of their feet during the heat sensations, and almost never is there accompanying tenderness along with it.

Diffuse palmoplantar keratoderma is a type of palmoplantar keratoderma that is characterized by an even, thick, symmetric hyperkeratosis over the whole of the palm and sole, usually evident at birth or in the first few months of life. Restated, diffuse palmoplantar keratoderma is an autosomal dominant disorder in which hyperkeratosis is confined to the palms and soles. The two major types can have a similar clinical appearance:

- "Diffuse epidermolytic palmoplantar keratoderma" (also known as "Palmoplantar keratoderma cum degeneratione granulosa Vörner," "Vörner's epidermolytic palmoplantar keratoderma", and "Vörner keratoderma") is one of the most common patterns of palmoplantar keratoderma, an autosomal dominant condition that presents within the first few months of life, characterized by a well-demarcated, symmetric thickening of palms and soles, often with a "dirty" snakeskin appearance due to underlying epidermolysis.

- "Diffuse nonepidermolytic palmoplantar keratoderma" (also known as "Diffuse orthohyperkeratotic keratoderma," "Hereditary palmoplantar keratoderma," "Keratosis extremitatum progrediens," "Keratosis palmoplantaris diffusa circumscripta," "Tylosis," "Unna–Thost disease", and "Unna–Thost keratoderma") is inherited as an autosomal dominant condition and is present from infancy, characterized by a well-demarcated, symmetric, often "waxy" keratoderma involving the whole of the palms and soles.

It is characterized by enlargement of the lymph nodes near the inner border of the lungs (called "hilar lymphadenopathy") as seen on x-ray, and tender red nodules (erythema nodosum) are classically present on the shins, predominantly in women. It may also be accompanied by arthritis (more prominent in men) and fever. The arthritis is often acute and involves the lower extremities.

Löfgren syndrome consists of the triad of erythema nodosum, bilateral hilar lymphadenopathy on chest radiograph, and arthralgia.

The typical rash commonly appears on buttocks. This then resembles the colour of a baboon’s buttocks. Other areas like upper inner thigh and armpits, may be affected by the rash. The rashes are red and well-defined. The presentation is typically symmetrical and not associated with systemic symptoms.

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.

Palmar erythema is reddening of the palms at the thenar and hypothenar eminences.

The rings are barely raised and are non-itchy. The face is generally spared.

Gianotti–Crosti syndrome ( ), also known as infantile papular acrodermatitis, papular acrodermatitis of childhood, and papulovesicular acrolocated syndrome, is a reaction of the skin to a viral infection. Hepatitis B virus and Epstein–Barr virus are the most frequently reported pathogens. Other incriminated viruses are hepatitis A virus, hepatitis C virus, cytomegalovirus, coxsackievirus, adenovirus, enterovirus, rotavirus, rubella virus, HIV, and parainfluenza virus.

It is named for Ferdinando Gianotti and Agostino Crosti.

It is associated with various physiological as well as pathological changes, or may be a normal finding:

- Portal hypertension

- Chronic liver disease (including chronic hepatitis)

- Pregnancy

- Polycythemia

- Thyrotoxicosis

- Rheumatoid arthritis (especially in patients with polycythaemia)

- Eczema and psoriasis

- Deep telangiectasias

- Coxsackievirus A infection (Hand, foot and mouth disease)

- Rocky Mountain spotted fever

- Secondary syphilis

- Kawasaki disease

- Adverse drug reaction: palmoplantar erythrodysesthesia (acral erythema)

Because circulating levels of estrogen increase in both cirrhosis and pregnancy, estrogen was thought to be the cause for the increased vascularity. More recently, nitric oxide has been implicated in the pathogenesis of palmar erythema.

Symmetrical drug-related intertriginous and flexural exanthema (SDRIFE), more popularly known as Baboon syndrome because of its resemblance to the distinctive red buttocks displayed by female baboons, is a systemic contact dermatitis characterized by well-demarcated patches of erythema distributed symmetrically on the buttocks.

The cause of the syndrome may be drug-related, i.e. induced by systemic administration of hydroxyzine penicillin, iodinated radio contrast media and others.

Burning feet syndrome can be inherited, or it can be caused by pressure being put on the nerves. Links also exist between this syndrome and diseases such as hypothyroidism, diabetes, and rheumatoid arthritis; links are also "believed" to exist between this syndrome and vitamin B (specifically pantothenic acid) deficiencies and renal failure.

It seems to be a small fiber neuropathy.

Annular erythema of infancy is a skin condition reported in children roughly six months in age, characterized by transitory skin lesions that resolved without treatment within eleven months.

Keratosis pilaris atrophicans faciei (also known as "Folliculitis rubra," "Keratosis pilaris rubra atrophicans faciei," "Lichen pilare," "Lichen pilaire ou xerodermie pilaire symetrique de la face," "Ulerythema ophryogenes," and "Xerodermie pilaire symetrique de la face") begins in infancy as follicular papules with perifollicular erythema. Initially, the lesions are restricted to the lateral eyebrows, but with time spread to involve the cheeks and forehead, and may also be associated with keratosis pilaris on the extremities and buttocks.

Often no specific cause for the eruptions is found. However, it is sometimes linked to underlying diseases and conditions such as:

- Food (including blue cheese or tomatoes).

- Contact Dermatitis (i.e. cleaning agents, fabric softeners, etc.)

- Fungal, Bacterial and Viral infections such as sinusitis, tuberculosis, candidiasis or tinea.

- Drugs including finasteride, etizolam (and benzodiazepines), chloroquine, hydroxychloroquine, oestrogen, penicillin and amitriptyline.

- Cancer (especially the type known as erythema gyratum perstans, in which there are concentric and whirling rings).

- Primary biliary cirrhosis.

- Graves disease.

- Appendicitis.

- Lupus

- Pregnancy (EAC usually disappears/stops soon after delivery of baby).

- Hormone (Contraceptive Pill, Stress, Hormone Drugs)

- Lyme Disease

Löfgren syndrome is a type of acute sarcoidosis that is frequent in Scandinavian, Irish, African and Puerto Rican women. It was described in 1953 by Sven Halvar Löfgren, a Swedish clinician. Some have considered the condition to be imprecisely defined.