During diagnosis it is important to determine the type of hand eczema and plan specific treatment accordingly. An additional diagnosis of allergies will indicate whether contact allergies or atopy diathesis are the cause of the hand eczema. Discussion concerning frequency of contact with water, irritants, and allergens in private and professional environments will also help evaluate individual stresses on the patient's skin. The hands may also exhibit various other skin illnesses and potential fungal infection or psoriasis must be ruled out. Usually, taking the patient’s personal history into account will help provide an accurate diagnosis.

Patch testing has been found to be helpful in the diagnosis of hand eczema.

Dyshidrosis is diagnosed clinically, by gathering a patient's history and making careful observations (see signs and symptoms section). Severity of symptoms can also be assessed using the dyshidrotic eczema area and severity index (DASI). The DASI has been designed for clinical trials and is not typically used in practice.

Most cases are well managed with topical treatments and ultraviolet light. About 2% of cases are not. In more than 60% of young children, the condition subsides by adolescence.

Atopic dermatitis is typically diagnosed clinically, meaning it is diagnosed based on signs and symptoms alone, without special testing. Several different forms of criteria developed for research have also been validated to aid in diagnosis. Of these, the UK Diagnostic Criteria, based on the work of Hanifin and Rajka, has been the most widely validated.

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.

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.

Hand eczema is a common condition: study data indicates a one-year prevalence of up to 10% in the general population. It is estimated that only 50–70% of people affected consult a doctor. The frequency of severe, chronic and recurrent forms of hand eczema is estimated at 5–7%. Approximately 2–4% of hand eczema patients also report that external (topical) therapy is insufficient.

Several factors adversely affect the long-term prognosis, including the development of the condition prior to the 20th birthday, the severity of initial manifestations, and eczema during childhood. Women, especially those under 30, are more frequently affected than men.

Possible treatments include minimizing diaper use, barrier creams, mild topical cortisones, and antifungal agents. A variety of other inflammatory and infectious processes can occur in the diaper area and an awareness of these secondary types of diaper dermatitis aids in the accurate diagnosis and treatment of patients.

The most effective treatment, although not the most practical one, is to discontinue use of diapers, allowing the affected skin to air out. Another option is simply to increase the frequency of diaper changing. Thorough drying of the skin before diapering is a good preventive measure because it is the excess moisture, either from urine and feces or from sweating, that sets the conditions for a diaper rash to occur.

The pathophysiology may involve a mixture of type I and type IV-like hypersensitivity reactions.

Other rashes that occur in a widespread distribution can look like an id reaction. These include atopic dermatitis, contact dermatitis, dyshidrosis, photodermatitis, scabies and drug eruptions.

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.

The prevalence of nummular dermatitis in the United States is approximately 2 per 1,000. It is considered a disease of adulthood, for it is rare in children.

Diagnosis of nummular dermatitis largely clinical. Biopsies are typically not necessary, and cannot be used to rule out other atopic dermatitis or other eczemas. However, patch testing may be employed to rule out irritants (contact dermatitis) as a cause. In children, nummular dermatitis is commonly confused with tinea corporis.

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.

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.

Gastritis or stomach upset is a common irritating disorder affecting millions of people. Gastritis is basically inflammation of the stomach wall lining and has many causes. Smoking, excess alcohol consumption and the use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, account for the majority of causes of gastritis. In some cases, gastritis may develop after surgery, a major burn, infection or emotional stress. The most common symptoms of gastritis include sharp abdominal pain which may radiate to the back. This may be associated with nausea, vomiting, abdominal bloating and a lack of appetite. When the condition is severe it may even result in loss of blood on the stools. The condition often comes and goes for years because most people continue to drink alcohol or use NSAIDs. Treatment includes the use of antacids or acid neutralizing drugs, antibiotics, and avoiding spicy food and alcohol.

One way to treat xerotic eczema is to avoid ing the affected area and to apply anti-itch or moisturizing lotion frequently.

A study published in 2005 found positive results from soaking the affected area in water for twenty minutes and then applying mid- to high-strength corticosteroid ointment.

One of the most common areas of the body associated with irritation is the vagina. Many women complain of an itch, dryness, or discharge in the perineum at some point in their lives. There are several causes of vaginal irritation including fungal vaginitis (like candida) or trichomoniasis. Often, herpes simplex infection of the mouth or genitalia can be recurrent and prove to be extremely irritating.

Sometimes, the irritation can be of the chronic type and it can be so intense that it also causes painful intercourse. Aside from infections, chronic irritation of the vagina may be related to the use of contraceptives and condoms made from latex. The majority of contraceptives are made of synthetic chemicals which can induce allergies, rash and itching. Sometimes the lubricant used for intercourse may cause irritation.

Another cause of irritation in women is post menopausal vaginitis. The decline in the female sex hormones leads to development of dryness and itching in the vagina. This is often accompanied by painful sexual intercourse. Cracks and tears often develop on outer aspects of the labia which becomes red from chronic scratching. Post menopausal vaginitis can be treated with short term use of vaginal estrogen pessary and use of a moisturizer.

The diagnosis of nipple discharge will be determined upon an examination by a health provider who will ask questions about symptoms and medical history. Tests that may be done include:

- Prolactin blood test

- Thyroid blood tests

- Head CT scan or MRI to look for pituitary tumor

- Mammography

- Ultrasound of the breast

- Breast biopsy

- Ductography or ductogram: an x-ray with contrast dye injected into the affected milk duct

- Skin biopsy, if Paget disease is a concern

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.

Breast eczema (also known as "Nipple eczema") may affect the nipples, areolae, or surrounding skin, with eczema of the nipples being of the moist type with oozing and crusting, in which painful fissuring is frequently seen, especially in nursing mothers. It will often occur in pregnancy even without breast feeding.

Persisting eczema of the nipple in the middle-aged and elderly needs to be discussed with a doctor, as a rare type of breast cancer called Paget's disease can cause these symptoms.

Most of the time, nipple problems are not breast cancer. These problems will either go away with the right treatment, or they can be watched closely over time.

The diagnosis of mastitis and breast abscess can usually be made based on a physical examination. The doctor will also take into account the signs and symptoms of the condition.

However, if the doctor is not sure whether the mass is an abscess or a tumor, a breast ultrasound may be performed. The ultrasound provides a clear image of the breast tissue and may be helpful in distinguishing between simple mastitis and abscess or in diagnosing an abscess deep in the breast. The test consists of placing an ultrasound probe over the breast.

In cases of infectious mastitis, cultures may be needed in order to determine what type of organism is causing the infection. Cultures are helpful in deciding the specific type of antibiotics that will be used in curing the disease. These cultures may be taken either from the breast milk or of the material aspirated from an abscess.

Mammograms or breast biopsies are normally performed on women who do not respond to treatment or on non-breastfeeding women. This type of tests is sometimes ordered to exclude the possibility of a rare type of breast cancer which causes symptoms similar to those of mastitis.

Tetter refers to any skin condition characterized by reddish vesicular eruptions and intense itching. Common diseases called tetter include:

- Eczema and Duhring's disease

- Herpes

- Porphyria cutanea tarda (PCT)

- Psoriasis

- Ringworm and jock itch