Eczema vaccinatum is a serious medical condition that requires immediate and intensive medical care. Therapy has been supportive, such as antibiotics, fluid replacement, antipyretics and analgesics, skin healing, etc.; vaccinia immune globulin (VIG) could be very useful but supplies may be deficient as of 2006. Antiviral drugs have been examined for activity in pox viruses and cidofovir is believed to display potential in this area.

With no particular affinity to any particular ethnic group, seen in all age groups and equally amongst males and females, the precise prevalence is not known.

In March 2007, a two-year-old Indiana boy and his mother contracted the life-threatening vaccinia infection from his father who was vaccinated against smallpox as part of the standard vaccination protocol for individuals serving in the US armed forces beginning in 2002. The child developed the pathognomonic rash which typifies eczema vaccinatum over 80 percent of his body surface area. The boy has a history of eczema, which is a known risk factor for vaccinia infection.

A full recovery is expected with treatment. Recurrent id reactions are frequently due to inadequate treatment of the primary infection or dermatitis and often the cause of recurrence is unknown.

It can be treated with systemic antiviral drugs, such as aciclovir or valganciclovir. Foscarnet may also be used for immunocompromised host with Herpes simplex and acyclovir-resistant Herpes simplex.

In adults, the prevalence of IgE sensitization to allergens from house dust mite and cat, but not grass, seem to decrease over time as people age. However, the biological reasons for these changes are not fully understood.

There is no good evidence that a mother's diet during pregnancy, the formula used, or breastfeeding changes the risk. There is tentative evidence that probiotics in infancy may reduce rates but it is insufficient to recommend its use.

People with eczema should not get the smallpox vaccination due to risk of developing eczema vaccinatum, a potentially severe and sometimes fatal complication.

Corticosteroids: For years, there was no treatment for atopic eczema. Atopy was believed to be allergic in origin due to the patients’ extremely high serum IgE levels, but standard therapies at the time did not help. Oral prednisone was sometimes prescribed for severe cases. Wet wraps (covering the patients with gauze) were sometimes used in hospitals to control itching. However, the discovery of corticosteroids in the 1950s, and their subsequent incorporation in topical creams and ointments, provided a significant advancement in the treatment of atopic eczema and other conditions. Thus, the use of topical steroids avoided many of the undesirable side-effects of systemic administration of corticosteroids. Topical steroids control the itching and the rash that accompany atopic eczema. Side-effects of topical steroid use are plentiful, and the patient is advised to use topical steroids in moderation and only as needed.

Immune modulators: Pimecrolimus and tacrolimus creams and ointments became available in the 1980s and are sometimes prescribed for atopic eczema. They act by interfering with T cells but have been linked to the development of cancer.

Avoiding dry skin: Dry skin is a common feature of patients with atopic eczema (see also eczema for information) and can exacerbate atopic eczema.

Avoiding allergens and irritants: See eczema for information.

Bathing once or more a day is recommended, usually for five to ten minutes in warm water. Soaps should be avoided as they tend to strip the skin of natural oils and lead to excessive dryness.

There has not been adequate evaluation of changing the diet to reduce eczema. There is some evidence that infants with an established egg allergy may have a reduction in symptoms if eggs are eliminated from their diets. Benefits have not been shown for other elimination diets, though the studies are small and poorly executed. Establishing that there is a food allergy before dietary change could avoid unnecessary lifestyle changes.

People can wear clothing designed to manage the itching, scratching and peeling.

The role of vitamin D on atopic dermatitis is not clear, but there is some evidence that vitamin D supplementation may improve its symptoms.

Studies have investigated the role of long chain polyunsaturated fatty acids (LCPUFA) supplementation and LCPUFA status in the prevention and treatment of atopic diseases, but the results are controversial. It remains unclear if the nutritional intake of n-3 fatty acids has a clear preventive or therapeutic role, or if n-6 fatty acids consumption promotes atopic diseases.

Several probiotics seem to have a positive effect with a roughly 20% reduction in the rate of atopic dermatitis. The best evidence is for multiple strains of bacteria.

In people with celiac disease or non-celiac gluten sensitivity, a gluten free diet improves their symptoms and prevents the occurrence of new outbreaks.

Treatment differs according to what rash a patient has been diagnosed with. Common rashes can be easily remedied using steroid topical creams (such as hydrocortisone) or non-steroidal treatments. Many of the medications are available over the counter in the United States.

The problem with steroid topical creams i.e. hydrocortisone; is their inability to penetrate the skin through absorption and therefore not be effective in clearing up the affected area, thus rendering the hydrocortisone almost completely ineffective in all except the most mild of cases.

First of all, catalysts for the development of chronic hand eczema, such as skin-irritating damage, excessive contact with water or proven allergenic substances, must be strictly removed and avoided. Treatment of every type of hand eczema and degree of severity must include sustainable replenishment of the natural oils and moisture contained in the skin with creams and salves free of fragrances and preservatives; this is an essential basic step. In addition, protection procedures developed especially for the individual's skin stresses must be applied, e.g. use of cotton or hypoallergenic plastic gloves. Depending on the individual's own needs, these procedures should continue after the hand eczema heals, since they will also have a preventative effect.

Dermographism can be treated by substances (i.e. an antihistamine) which prevent histamine from causing the reaction. These may need to be given as a combination of H antagonists, or possibly with an H-receptor antagonist such as cimetidine.

OTC Vitamin C, 1000 mg daily, increases histamine degradation and removal.

Not taking hot baths or showers may help if it is generalized (all over) and possibly for localized cases (in a specific area). If taking hot showers helps, it may be a condition called shower eczema. If it affects mainly the head, it may be psoriasis. In rare cases, allergy tests may uncover substances the patient is allergic to.

While cromoglycate, which prevents histamine from being released from mast cells, is used topically in rhinitis and asthma, it is not effective orally for treating chronic urticaria.

Common causes of rashes include:

- Food allergy

- Medication side effects

- Anxiety

- Allergies, for example to food, dyes, medicines, insect stings, metals such as zinc or nickel; such rashes are often called hives.

- Skin contact with an irritant

- Fungal infection, such as ringworm

- Balsam of Peru

- Reaction to vaccination

- Skin diseases such as eczema or acne

- Exposure to sun (sunburn) or heat

- Friction due to chafing of the skin

- Irritation such as caused by abrasives impregnated in clothing rubbing the skin. The cloth itself may be abrasive enough for some people

- Secondary syphilis

- Poor personal hygiene

Uncommon causes:

- Autoimmune disorders such as psoriasis

- Lead poisoning

- Pregnancy

- Repeated scratching on a particular spot

- Lyme Disease

- Scarlet fever

Hand eczema is a complex condition, and treatment should only be administered by a dermatologist with specialist knowledge. Treatment may be very costly. Treatment should follow certain basic principles, and chronic and severe cases of hand eczema in particular require complex treatment concepts. Besides skin care, hand protection, and external (topical) applications with preparations containing effective ingredients or light therapy, an internal (systemic) therapy may be considered.

This infection affects multiple organs, including the eyes, brain, lung, and liver, and can be fatal.

Applying moisturisers may prevent the skin from drying out and decrease the need for other medications. Affected persons often report that improvement of skin hydration parallels with improvement in AD symptoms.

Health professionals often recommend that persons with AD bathe regularly in lukewarm baths, especially in salt water, to moisten their skin. Avoiding woollen clothing is usually good for those with AD. Likewise silk, silver-coated clothing may help. Dilute bleach baths have also been reported effective at managing AD.

Allergen immunotherapy (AIT) treatment involves administering doses of allergens to accustom the body to substances that are generally harmless (pollen, house dust mites), thereby inducing specific long-term tolerance. Allergy immunotherapy can be administered orally (as sublingual tablets or sublingual drops), or by injections under the skin (subcutaneous). Discovered by Leonard Noon and John Freeman in 1911, allergy immunotherapy represents the only causative treatment for respiratory allergies.

Experimental research has targeted adhesion molecules known as selectins on epithelial cells. These molecules initiate the early capturing and margination of leukocytes from circulation. Selectin antagonists have been examined in preclinical studies, including cutaneous inflammation, allergy and ischemia-reperfusion injury. There are four classes of selectin blocking agents: (i) carbohydrate based inhibitors targeting all P-, E-, and L-selectins, (ii) antihuman selectin antibodies, (iii) a recombinant truncated form of PSGL-1 immunoglobulin fusion protein, and (iv) small-molecule inhibitors of selectins. Most selectin blockers have failed phase II/III clinical trials, or the studies were ceased due to their unfavorable pharmacokinetics or prohibitive cost. Sphingolipids, present in yeast like "Saccharomyces cerevisiae" and plants, have also shown mitigative effects in animal models of gene knockout mice.

Antihistamines such as diphenhydramine and chlorpheniramine are commonly used as treatment. People treated with H1 antihistamines exhibit reduced production of histamine and leukotrienes as well as downregulation of adhesion molecule expression on the vasculature which in turn attenuates allergic symptoms by 40–50%.

Dual-action medications are also prescribed frequently. Olopatadine (Patanol) and ketotifen fumarate (Alaway or Zaditor) both provide protection by acting as an antihistamine and a mast cell stabilizer together. Patanol is a prescription medication, whereas ketotifen fumarate is not.

A systematic review of 30 trials, with 17 different treatment comparisons found that all topical antihistamines and mast cell stabilizers included for comparison were effective in reducing symptoms of seasonal allergic conjunctivitis. There was not enough evidence to determine differences in long-term efficacy among the treatments.

Many of the eye drops can cause burning and stinging, and have side-effects. Proper eye hygiene can improve symptoms, especially with contact lenses. Avoiding precipitants, such as pollen or mold can be preventative.

One of the keys to treatment and prevention involves keeping the skin moisturized. Lotions, creams, and bath oils may help prevent an outbreak. If the condition flares up, a common treatment involves the application of topical corticosteroids. Oral antihistamines may help lessen itching. Avoidance of irritants is a common strategy. More severe cases sometimes respond to ultraviolet light treatment.

There are many treatments available for dyshidrosis. However, few of them have been developed or tested specifically on the condition.

- Barriers to moisture and irritants, including barrier creams and gloves.

- Topical steroids - while useful, can be dangerous long-term due to the skin-thinning side-effects, which are particularly troublesome in the context of hand dyshidrosis, due to the amount of toxins and bacteria the hands typically come in contact with.

- Potassium permanganate dilute solution soaks - also popular, and used to 'dry out' the vesicles, and kill off superficial "Staphylococcus aureus", but it can also be very painful. Undiluted it may cause significant burning.

- Dapsone (diamino-diphenyl sulfone), an antibacterial, has been recommended for the treatment of dyshidrosis in some chronic cases.

- Antihistamines: Fexofenadine up to 180 mg per day.

- Alitretinoin (9-cis-retinoic acid) has been approved for prescription in the UK. It is specifically used for chronic hand and foot eczema. It is made by Basilea of Switzerland (BAL 4079).

- Systemic steroids can be taken orally to treat especially acute and severe cases of dyshidrosis.

Dermatographic urticaria (also known as dermographism, dermatographism or "skin writing") is a skin disorder and one of the most common types of urticaria affecting 2–5% of the population.

The exact causes of dyshidrosis are unknown. In 2013, a randomized, double-blind, placebo-controlled cross-over study by the University Medical Center Groningen reported that dyshydrosis outbreaks on the hands increased significantly among those allergic to house dust mites, following inhalation of house dust mite allergen.

Food allergens may be involved in certain cases. Cases studies have implicated a wide range of foods including tuna, tomato, pineapple, chocolate, coffee, and spices among others. A number of studies have implicated balsam of Peru.

Id reaction and irritant contact dermatitis are possible causes.

Many contact sensitizers or irritants are known to cause contact dermatitis superimposed on nummular dermatitis. Studies have implicated nickel, cobalt, chromate, and fragrance as likely culprits. Xerosis, or dehydration of skin is also a likely cause. Infection with "Staphylococcus aureus" bacteria or "Candida" may also play a role.

Rosin, the material commonly used to wax string instruments is known to cause allergic contact dermatitis in musicians. Nickel, a metal found in musical instruments causes allergic contact dermatitis on the fingers and hands of string instrumentalists and in the lip and neck of wind instrumentalists. Wind instrumentalists with lip and neck infection should switch to gold or plastic mouthpieces if allergic dermatitis occurs. (R)-4-methoxydalbergione present in rosewood may cause allergic contact dermatitis in violinists. Cane reed (causing chelitis in saxophone players), propolis (a wax used to close structural gaps in musical instruments), paraphenylenediamine (used to polish musical instruments) and potassium dichromate (tanning agent to the skin of the harp) also cause allergic contact dermatitis in musicians.