The term dermatitis generally refers to a skin inflammation caused by various factors triggering a skin reaction. There are different forms of dermatitis.

Atopic Dermatitis

What Is Atopic Dermatitis?

Also known as constitutional eczema, atopic dermatitis is a skin inflammation causing itchy skin and visible redness.

Its presence can interfere with everyday life, significantly worsening its quality because itching can impair night’s sleep and thus reduce the ability to focus while studying or working. In addition, atopic dermatitis also negatively affects self-esteem and sociality because of the frequent localization of disease in highly visible areas of the skin. 

Sometimes, when atopic dermatitis becomes chronic, or the sufferer continually scratches, the skin may thicken (lichenification).

In babies, it may occur as early as birth with abundant milk crusts or in the first months or years of the child, usually with sudden onset. However, it may also occur in adults.

Typically, atopic dermatitis affects:

  • Hands
  • Feet
  • The inner crease of the elbow
  • Back crease of the knees
  • Wrists
  • Ankles
  • Face
  • Neck
  • Chest
  • The area around the eyes

What Are the Causes of Atopic Dermatitis?

Atopic dermatitis has a multifactorial basis consisting of genetic, environmental, and immunological factors.

People with atopic dermatitis, due to a defect in their skin barrier, come into contact with various allergens, triggering the inflammatory response.

Factors such as the change of season and psychophysical stress can exacerbate the clinical picture.

The direct cause-effect relationship between food allergens and atopic dermatitis is considered quite rare, so elimination diets, especially in pediatric age, are considered unnecessary and potentially harmful.

What Are the Symptoms of Atopic Dermatitis?

Atopic dermatitis manifests with red patches (which may be covered with blisters, excoriations, or crusts) on dry, itchy skin. Itching may vary in intensity from person to person and tends to worsen overnight.

Atopic Dermatitis: What Tests for a Diagnosis?

There are no specific tests to diagnose atopic dermatitis, but a dermatologic examination with observation of symptoms by a specialist is usually needed.

In some cases, measuring the total IgE level may help to distinguish intrinsic from extrinsic forms without, however, significant therapeutic implications.

How Is Atopic Dermatitis Treated and How to Soothe Itching?

Treatment of atopic dermatitis varies according to its severity.

Mild forms require topical corticosteroid medications or some immunomodulators for local use, such as tacrolimus and pimecrolimus. If atopic dermatitis involves extensive areas of the skin, phototherapy may also be useful.

Taking oral antihistamines may be indicated to control itching and thus reduce scratching.

Local or systemic antibiotic therapies may be useful in cases of bacterial infection (impetiginization) of the lesions.

Systemic steroids or other immunosuppressants, such as cyclosporine, are prescribed for the more severe forms of atopic dermatitis. 

Monoclonal antibodies such as dupilumab or tralokinumab or janus kinase inhibitors (upadacitinib, baricitinib) may also be used.

What To Do to Prevent Atopic Dermatitis?

To prevent atopic dermatitis, it is advised to:

  • Avoid too long and frequent bathing and washing because, together with aggressive cleansers, these actions deplete the outer layers of the protecting skin;
  • Dry the skin gently, without rubbing it;
  • Avoid wearing synthetic fiber clothing;
  • Expose to the sun using specific sunscreens suitable for your skin type;
  • Use moisturizing and soothing creams and gentle cleansers daily. 

Atopic Dermatitis and Mask Use

Although often necessary and appropriate, prolonged mask use in people with atopic dermatitis may be responsible for worsening the skin condition. Face masks are mainly made of synthetic materials, which include allergenic substances, sanitizers, and dyes that can lead to a sudden aggravation of the skin symptoms of atopic dermatitis. In addition, since they have an occluding effect, they alter the skin microenvironment by increasing moisture and compromising its barrier function, resulting in drier skin and the risk of bacterial infection. 

Pressure and mechanical rubbing of the mask on the skin can also create skin erosions that are particularly painful on atopic skin. 

It is advisable to keep the skin well moisturized and not hesitate to consult a dermatologist if needed. 

In general, however, some good practices can be adopted to reduce the risk of skin discomfort related to mask use:

  • Moisturizing the skin using appropriate creams, soothing products, and possibly local corticosteroids (prescription only);
  • Using masks of appropriate size, neither too wide nor too narrow. The mask should adhere to the contours of the face without exerting excessive pressure;
  • Using non-comedogenic make-up products to avoid further occlusion of the pores.

Seborrheic Dermatitis

What Is Seborrheic Dermatitis?

Seborrheic dermatitis is associated with skin inflammation affecting areas of the skin that are rich in sebaceous glands, such as the scalp, naso-genital grooves, retroauricular areas, superciliary arches, and sternal areas.

In mild form, this type of dermatitis manifests as scales that do not adhere to the scalp (known as dandruff), while in a more severe form, the disease may also be present with erythematous plaques covered with greasy yellow-like scales.

Seborrheic dermatitis is not contagious; it usually occurs around the age of 30-40 years and tends to become chronic (excluding neonatal and infant forms), with a greater occurrence in men.

What Are the Causes of Seborrheic Dermatitis?

The cause of seborrheic dermatitis is not well defined. However, it is known that an overgrowth of yeasts of the genus Malassezia, commonly found on the skin, may be responsible for the scaling and inflammation.

Seborrheic dermatitis can also flare up due to certain factors, such as:

  • Hormonal imbalances (particularly during the change of seasons)
  • Psychophysical stress
  • Genetic predisposition

What Are the Symptoms of Seborrheic Dermatitis?

Seborrheic dermatitis typically manifests with:

  • Yellowish-white scales that break away from the skin (known as dandruff if present on the scalp)
  • Skin irritation
  • Itching
  • Intense skin dryness

Seborrheic Dermatitis: What Tests for a Diagnosis?

A dermatologic examination should be performed to diagnose seborrheic dermatitis.

How to Treat Seborrheic Dermatitis?

To treat seborrheic dermatitis, it is necessary to counteract the reproduction of Malassezia and the scaling process. The most commonly used products are shampoos and creams based on ketoconazole, ciclopirox, selenium sulfide, or salicylic acid. Treatment with these products should be done more frequently when symptoms are more severe, while during periods of remission, mild shampoos for frequent washing may be preferred.

Cortisone-based topical treatments may be helpful in more severe forms and as short-term treatments.

How to Prevent Seborrheic Dermatitis?

There are no specific measures to prevent the onset of seborrheic dermatitis. However, it is recommended to:

  • Avoid too frequent and aggressive bathing and washing, which deplete the skin’s protective surface layers;
  • Avoid scratching and peeling off the scales so as not to feed a vicious cycle of new inflammation and dermatitis;
  • As the sun’s rays can actually reduce inflammation, sun exposure is recommended, but with proper care.

Allergic Contact Dermatitis

What Is Allergic Contact Dermatitis?

Allergic contact dermatitis is an allergic skin reaction that is triggered by contact with chemical or natural substances, causing an immunologic response. These substances are called allergens, and when the skin comes into contact with them, an inflammatory reaction develops and causes itching.

What Are the Causes of Allergic Contact Dermatitis?

Repeated contact with chemical or environmental allergens is the cause of allergic contact dermatitis.

Some examples of allergens are:

  • Certain metals
  • Dyes
  • Resins
  • Preservatives
  • Oils and essences of plants and flowers

Allergic contact dermatitis can affect any part of the body, depending on the individual allergen, such as hair dye in the case of the scalp or nickel in the case of earlobes and palms.

What Are the Symptoms of Allergic Contact Dermatitis?

Typically, allergic contact dermatitis has a sudden onset and manifests with symptoms such as:

  • Red erythematous patches
  • Blistering blisters
  • Scabs

The rash may also be itchy.

Allergic Contact Dermatitis: What Tests to Do for Diagnosis?

To obtain a diagnosis of allergic contact dermatitis, a dermatologist can perform patch testing, an allergy test that can detect the substances responsible for the dermatitis. The test is performed by applying small traces of purified allergens to the skin that are useful in identifying what caused the allergic reaction. The test is also valuable for distinguishing allergic reactions from irritative contact dermatitis

The result of the patch test is then correlated with the patient’s clinical information to assess a possible correlation between dermatitis and contact with the potential allergen. 

How Is Allergic Contact Dermatitis Treated?

The first step in treating this form of dermatitis is avoiding contact with the allergen responsible for the reaction. 

A cortisone-based cream may help keep the rash under control.

Lastly, it is best to wash the skin with gentle soaps and use moisturizing and emollient products after washing.

How to Prevent Allergic Contact Dermatitis?

The only way to prevent allergic contact dermatitis is to avoid contact with the allergens responsible for the reaction after they have been discovered.

Irritative Contact Dermatitis

What is Irritative Contact Dermatitis?

Irritative contact dermatitis is a skin inflammation due to certain chemical and physical stimuli. It usually affects areas such as the hands, neck, and face that are exposed to external contact. However, a typical irritative dermatitis is diaper dermatitis, which affects the skin area covered by the diaper due to prolonged contact with feces and urine.

What Causes Irritative Contact Dermatitis?

Irritative dermatitis results from repeated and/or prolonged contact with irritating stimuli. Substances that most often trigger it include:

  • Surfactants, alcohols, and antiseptics that can be found in the household but also in personal cleaners;
  • Solvents, acids, caustics, and glass wool, which are frequent, especially in professional settings;
  • Substances released by some plants.

What Are the Symptoms of Irritative Contact Dermatitis?

Shortly after coming in contact with the irritant, or a few hours later, the skin experiences a local inflammatory reaction. 

Typically, red patches suddenly appear, and other symptoms may also occur, such as:

  • Blisters
  • Skin erosions
  • Desquamation
  • Scabs

The rash is associated with burning or itching that prompts scratching, promoting, in turn, an infection.

Sometimes, sensitization to the irritant, which may not have been a particular problem initially, can develop such that one becomes allergic to it, resulting in allergic contact dermatitis.

Irritative Contact Dermatitis: What Tests for a Diagnosis?

A dermatologic examination is usually sufficient for diagnosis. Allergy tests (such as patch testing) can be used to rule out an allergic form.

How Is Irritative Contact Dermatitis Treated?

In the presence of irritative contact dermatitis, soothing creams may be prescribed, and in case of a strong inflammatory reaction, cortisone creams can be used for a short period. 

How to Prevent Irritative Contact Dermatitis?

To prevent its onset and recurrence, it is best to avoid repeated and prolonged contact with irritants. However, this may be more difficult to implement for those exposed to them for professional reasons.

In general, to avoid contact with the irritant, it may be necessary to wear gloves, preferably with a cotton layer on the inside, when handling chemicals or in the case of contact with plants, and to avoid excessive hand washing, which could weaken the skin barrier and promote penetration of the irritants. 

In addition, it is recommended to apply emollient creams that can restore those lipids removed by irritants, thus contributing to the skin barrier function.