Scleroderma in pregnancy is a complex situation; it increases the risk to both mother and child. Overall scleroderma is associated with reduced fetal weight for gestational age. The treatment for scleroderma often includes known teratogens such as cyclophosphamide, methotrexate, mycophenolate, etc. and hence careful avoidance of such drugs during pregnancy is advised. In these cases hydroxychloroquine and low-dose corticosteroids might be used for disease control.

Lupus can develop in any age but most commonly in ages 15 to 44 with varying results. Typically, the manifestation of the disease tends to be more acute in those affected who are of younger age. Women are more likely to get it than men. Patients with juvenile onset Lupus in particular, are vulnerable to mucocutaneous manifestations of the disease (alopecia, skin rash, and ulceration of the mucus membranes) more so than any other age group. However, patients with late onset Lupus have a much higher mortality rate. Nearly 50% of those with late onset Lupus die of their affliction. Women who are of childbearing age are also particularly at risk.

Substantial data have been found to indicate that certain ethnic populations could be more at risk for Lupus Erythematosus, and have a better or worse prognosis. Asian, African, and Native Americans are more likely to get Lupus than Caucasians. Caucasians seem to generally have a more mild manifestation of the disease. Their survival rates after five years were typically around 94%-96%, while patients of African, and some Asian ethnicities had survival rates closer to 79%-92%. The only documented ethnicity that had a higher survival rate than Caucasians were Koreans, who had survival rates nearer to 98%. Among Caucasians, the most common causes of death were complications involving the cardiovascular system, the respiratory system and problems with malignancies. Atherosclerotic cardiovascular disease is more prevalent in African American Lupus patients compared to Caucasians with Lupus.

Scleroderma most commonly first presents between the ages of 20 and 50 years, although any age group can be affected. Women are four to nine times more likely to develop scleroderma than men.

This disease is found worldwide. In the United States, prevalence is estimated at 240 per million and the annual incidence of scleroderma is 19 per million people. Likewise in the United States, it is slightly more common in African Americans than in their white counterparts, Scleroderma occurs much more often in women than it does in men. Choctaw Native Americans are more likely than Americans of European descent to develop the type of scleroderma that affects internal organs. In Germany, the prevalence is between 10 and 150 per million people, and the annual incidence is between 3 and 28 per million people. In South Australia, the annual incidence is 23 per million people, and the prevalence 233 per million people. Scleroderma is less common in the Asian population.

Though the cause is not well understood, the disease is thought to be due to immune system dysfunction, and particularly improper functioning of neutrophils. In support of an immune cause, a variety of immune mediators such as IL-8, IL-1β, IL-6, interferon (IFN)-γ, G-CSF, TNF, matrix metallopeptidase (MMP)-9, MMP-10, and Elafin have all been reported to be elevated in patients with pyoderma gangrenosum.

Also in support of an immune cause is the finding that at least half of all pyoderma gangrenosum patients suffer from immune-mediated diseases. For instance, ulcerative colitis, rheumatoid arthritis, and multiple myeloma (MM) have all been associated with pyoderma gangrenosum. It can also be part of a syndromes such as PAPA syndrome.

One hallmark of pyoderma gangrenosum is pathergy, which is the appearance of new lesions at sites of trauma.

As PNP is ultimately caused by the presence of a tumor, it is not contagious. There is no known way to predict who will become afflicted with it. Patients with cancer are therefore a group at risk. Although PNP has been known to affect all age groups, it is more likely to afflict middle-aged to older patients.

Psoriasis has been associated with obesity and several other cardiovascular and metabolic disturbances. The incidence of diabetes is 27% higher in people affected by psoriasis than in those without the condition. Severe psoriasis may be even more strongly associated with the development of diabetes than mild psoriasis. Younger people with psoriasis may also be at increased risk for developing diabetes. Individuals with psoriasis or psoriatic arthritis have a slightly higher risk of heart disease and heart attacks when compared to the general population. Cardiovascular disease risk appeared to be correlated with the severity of psoriasis and its duration. There is no strong evidence to suggest that psoriasis is associated with an increased risk of death from cardiovascular events. Methotrexate may provide a degree of protection for the heart.

The odds of having hypertension are 1.58 times higher in people with psoriasis than those without the condition; these odds are even higher with severe cases of psoriasis. A similar association was noted in people who have psoriatic arthritis—the odds of having hypertension were found to be 2.07 times greater when compared to odds of the general population. The link between psoriasis and hypertension is not currently understood. Mechanisms hypothesized to be involved in this relationship include the following: dysregulation of the renin-angiotensin system, elevated levels of endothelin 1 in the blood, and increased oxidative stress. The incidence of the heart rhythm abnormality atrial fibrillation is 1.31 times higher in people with mild psoriasis and 1.63 times higher in people with severe psoriasis. There may be a slightly increased risk of stroke associated with psoriasis, especially in severe cases. Treating high levels of cholesterol with statins has been associated with decreased psoriasis severity, as measured by PASI score, and has also been associated with improvements in other cardiovascular disease risk factors such as markers of inflammation. These cardioprotective effects are attributed to ability of statins to improve blood lipid profile and because of their anti-inflammatory effects. Statin use in those with psoriasis and hyperlipidemia was associated with decreased levels of high-sensitivity C-reactive protein and TNFα as well as decreased activity of the immune protein LFA-1. Compared to individuals without psoriasis, those affected by psoriasis are more likely to satisfy the criteria for metabolic syndrome.

All patients with symptomatic cryoglobulinemia are advised to avoid, or protect their extremities, from exposure to cold temperatures. Refrigerators, freezers, and air-conditioning represent dangers of such exposure.

The following are conditions commonly associated with pyoderma gangrenosum:

- Inflammatory bowel disease:

- Ulcerative colitis

- Crohn's disease

- Arthritides:

- Rheumatoid arthritis

- Seronegative arthritis

- Hematological disease:

- Myelocytic leukemia

- Hairy cell leukemia

- Myelofibrosis

- Myeloid metaplasia

- Monoclonal gammopathy

- Autoinflammatory disease:

- Pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome (PAPA syndrome)

- Granulomatosis with polyangiitis

The rates of Crohn's disease and ulcerative colitis are increased when compared with the general population, by a factor of 3.8 and 7.5 respectively. People with psoriasis also have a higher risk of celiac disease. Few studies have evaluated the association of multiple sclerosis with psoriasis, and the relationship has been questioned. Psoriasis has been associated with a 16% increase in overall relative risk for non-skin cancer. People with psoriasis have a 52% increased risk cancers of the lung and bronchus, a 205% increase in the risk of developing cancers of the upper gastrointestinal tract, a 31% increase in the risk of developing cancers of the urinary tract, a 90% increase in the risk of developing liver cancer, and a 46% increase in the risk of developing pancreatic cancer. The risk for development of non-melanoma skin cancers is also increased. Psoriasis increases the risk of developing squamous cell carcinoma of the skin by 431% and increases the risk of basal cell carcinoma by 100%. There is no increased risk of melanoma associated with psoriasis.

Papular mucinosis affects adults of both sexes equally and appears between ages 30 and 80. Recently, it has been reported in patients infected with the HIV/AIDS virus.

Individuals found to have circulating cryoglobulins but no signs or symptoms of cryoglobulinemic diseases should be evaluated for the possibility that their cryoglobulinemia is a transient response to a recent or resolving infection. Those with a history of recent infection that also have a spontaneous and full resolution of their cryoglobulinemia need no further treatment. Individuals without a history of infection and not showing resolution of their cryoglobulinemia need to be further evaluated. Their cryoglobulins should be analyzed for their composition of immunoglobulin type(s) and complement component(s) and examined for the presence of the premalignant and malignant diseases associated with Type I disease as well as the infectious and autoimmune diseases associated with type II and type III disease. A study conducted in Italy on >140 asymptomatic individuals found five cases of hepatitis C-related and one case of hepatitis b-related cryoglobulinemia indicating that a complete clinical examination of asymptomatic individuals with cryoglobulinemia offers a means for finding people with serious but potentially treatable and even curable diseases. Individuals who show no evidence of a disease underlying their cryoglobulinemia and who remain asymptomatic should be followed closely for any changes that may indicate development of cryoglobulinemic disease.

If the lesions are mild, the patient will be subject to a good deal of pain. If the lesions are severe, the overall quality of life is devastating. The impaired skin barrier function commonly leads to localized infection, which sepsis and death may follow. The pain from the oral and pharyngeal ulcers interfere with eating, which can compromise nutritional health.

The general prognosis for PNP is poor. It is more hopeful if the tumor is benign, but in the case of malignant tumors, the mortality rate is roughly 90%. The two most commonly associated types of tumors are non-Hodgkin lymphoma and chronic lymphocytic lymphoma; nearly all of these patients die within two years of diagnosis. This is attributed to the effects of the tumor combined with the negative side effects of the medication administered to treat PNP.

Roughly 1/3 of the deaths from PNP stem from pulmonary insufficiency which is brought about by the action of PNP on the respiratory mucosa. It manifests as dyspnea and progresses to bronchiolitis obliterans (non-reversible obstructive lung disease) via an unknown mechanism.

Papular mucinosis (also known as "Scleromyxedema," "Generalized lichen myxedematosus," and "Sclerodermoid lichen myxedematosus") is a rare skin disease. Localized and disseminated cases are called papular mucinosis or lichen myxedematosus while generalized, confluent papular forms with sclerosis are called scleromyxedema. Frequently, all three forms are regarded as papular mucinosis. However, some authors restrict it to only mild cases. Another form, acral persistent papular mucinosis is regarded as a separate entity.

An overlap syndrome is an autoimmune disease of connective tissue in which a person presents with symptoms of two or more diseases.

Examples of overlap syndromes include mixed connective tissue disease and scleromyositis. Diagnosis depends on which diseases the patient shows symptoms and has positive antibodies for in their lab serology.

In overlap syndrome, features of the following diseases are found (most common listed):

- Systemic lupus erythematosus (SLE),

- Systemic sclerosis,

- Polymyositis,

- Dermatomyositis,

- Rheumatoid arthritis (RA)

- Sjögren's syndrome

- Eosinophilic granulomatosis with polyangiitis (EGPA)

- Autoimmune thyroiditis

- Antiphospholipid antibody syndrome

The treatment of overlap syndrome is mainly based on the use of corticosteroids and immunosuppressants. Biologic drugs, i.e. anti-TNFα or anti-CD20 monoclonal antibodies, have been recently introduced as alternative treatments in refractory cases. There are some concerns with the use of anti-TNF agents in patients with systemic autoimmune diseases due to the risk of triggering disease exacerbations.

In most cases of bullous pemphigoid, no clear precipitating factors are identified. Potential precipitating events that have been reported include exposure to ultraviolet light and radiation therapy. Onset of bullous pemphigoid has also been associated with certain drugs, including furosemide, and other nonsteroidal anti-inflammatory agents, captopril, penicillamine, and antibiotics.

Bullous pemphigoid may be self-resolving in a period ranging from several months to many years even without treatment. Poor general health related to old age is associated with a poorer prognosis.

The cause of prurigo nodularis is unknown, although other conditions may induce PN. PN has been linked to Becker's nevus, linear IgA disease, an autoimmune condition, liver disease and T cells. Systemic pruritus has been linked to cholestasis, thyroid disease, polycythaemia rubra vera, uraemia, Hodgkins disease, HIV and other immunodeficiency diseases. Internal malignancies, liver failure, renal failure, and psychiatric illnesses have been considered to induce PN, although more recent research has refuted a psychiatric cause for PN. Patients report an ongoing battle to distinguish themselves from those with psychiatric disorders such as delusions of parasitosis and other psychiatric conditions.

Prurigo nodularis (PN), also known as nodular prurigo, is a skin disease characterised by pruritic (itchy) nodules which usually appear on the arms or legs. Patients often present with multiple excoriated lesions caused by scratching. PN is also known as Hyde prurigo nodularis, "Picker's nodules", atypical nodular form of neurodermatitis circumscripta, lichen corneus obtusus.

Lichen simplex chronicus is a distinct clinical entity.

Lichen myxedematosus is a group of cutaneous disorders considered mucinoses. Conditions included in this group are:

Atypical lichen myxedematosus (also known as "Intermediate lichen myxedematosus") is a skin condition caused by fibroblasts producing abnormally large amounts of mucopolysaccharides.

Localized pustular psoriasis presents as two distinct conditions that must be considered separate from generalized psoriasis, and without systemic symptoms, these two distinct varieties being pustulosis palmaris et plantaris and acrodermatitis continua.

Nodular lichen myxedematosus is a cutaneous condition characterized by multiple nodules on the limbs and trunk, with a mild or absent papular component.

The life span in patients with Schnitzler syndrome has not been shown to differ much from the general population. Careful follow-up is advised, however. A significant proportion of patients develops a lymphoproliferative disorder as a complication, most commonly Waldenström's macroglobulinemia. This may lead to symptoms of hyperviscosity syndrome. AA amyloidosis has also been reported in people with Schnitzler syndrome.

Urticaria is a vascular reaction of the skin characterized by the appearance of wheals, which are firm, elevated swelling of the skin. Angioedema, which can occur alone or with

urticaria, is characterized by a well-defined, edematous swelling that involves subcutaneous tissues, abdominal organs, or upper airway.

- Acquired C1 esterase inhibitor deficiency

- Acute urticaria

- Adrenergic urticaria

- Anaphylaxis

- Aquagenic urticaria

- Cholinergic urticaria

- Chronic urticaria (ordinary urticaria)

- Cold urticaria

- Dermatographism (dermographism)

- Episodic angioedema with eosinophilia (Gleich's syndrome)

- Exercise urticaria (exercise-induced urticaria)

- Galvanic urticaria

- Heat urticaria

- Hereditary angioedema (Quincke's edema)

- Localized heat contact urticaria

- Mast cell-independent urticaria

- Physical urticaria

- Primary cold contact urticaria

- Pressure urticaria (delayed pressure urticaria)

- Reflex cold urticaria

- Schnitzler syndrome

- Secondary cold contact urticaria

- Solar urticaria

- Systemic capillary leak syndrome

- Urticarial allergic eruption

- Urticaria-like follicular mucinosis

- Vibratory angioedema