Dermatitis is defined as an inflammation of the skin characterized by specific symptoms, including erythema, vesicles, crusting, exudation, scaling, and, in some cases, edema, often accompanied by varying degrees of pruritus.
The condition may present as an acute episode or may exhibit a chronic, recurrent course. The etiological factors and clinical manifestations of dermatitis are diverse, encompassing infections, irritations, allergic reactions, and nutritional deficiencies, among others. Treatment modalities may include pharmacological interventions as well as topical creams or ointments aimed at alleviating symptoms and enhancing skin condition.
Dermatitis is a prevalent condition affecting both children and adults; it is non-contagious and generally not considered severe. Numerous scientific studies have been conducted to explore the various types of dermatitis.
The interest of researchers in this field is driven by several factors, including the observed increase in the incidence of these conditions over the past 30 to 50 years, the significant impact on the quality of life of affected individuals, and the associated social costs. The most common forms of dermatitis include atopic dermatitis, contact dermatitis (which accounts for nearly 90% of cases), seborrheic dermatitis, and stress-related dermatitis.
Understanding Dermatitis
The terms “eczema” and “dermatitis” refer to a range of conditions that share common symptoms, such as pruritus, erythema, vesiculation, and desquamation. This inflammatory skin disease is relatively common among both adults and children and is non-contagious.
Dermatitis may be localized to specific areas of the body (as seen in contact dermatitis or dyshidrosis) or may be more widespread (as in atopic dermatitis). It represents a defensive response of the skin to both internal (endogenous) factors, such as food allergies, and external (exogenous) factors, although both may occur concurrently. For instance, endogenous dermatitis may be exacerbated by contact with irritants such as detergents and solvents.
The severity of symptoms can vary significantly, ranging from mild dermatitis to chronic forms that may persist for weeks, months, or even years, often exhibiting periodic fluctuations influenced by seasonal changes and temperature.
The Skin and Its Primary Functions
The skin envelops the entire body and constitutes approximately 8% of total body mass. Its thickness ranges from 1.5 to 4 mm and serves as the primary interface between the body and the external environment. The skin functions as an effective barrier against microbial invasion, mechanical injury, chemical exposure, extreme temperatures, and ultraviolet (UV) radiation.
Additionally, the skin is involved in various biochemical processes, including the synthesis of vitamin D under the influence of ultraviolet B (UVB) rays, as well as the production of cytokines and growth factors. It plays a crucial role in thermoregulation by modulating blood flow to control body temperature.
The skin also participates in sexual communication and can reflect emotional states through muscular and vascular responses, making it one of the principal sensory organs equipped with nerve endings and specialized receptors for touch, temperature, pain, and other stimuli.
Skin color, which is genetically determined, is influenced by factors such as blood circulation, the thickness of the skin, and the activity of melanocytes, which produce the pigment melanin that offers protection against UV radiation. The overall health status of an individual is often mirrored in the condition of the skin, with early signs of many systemic diseases frequently manifesting on the skin.
Causes of Dermatitis
Identifying the precise causes of dermatitis can be challenging due to the multitude of factors that may trigger the condition. However, research indicates a genetic predisposition at birth that may render the skin more susceptible to these disorders.
In cases of irritant and allergic contact dermatitis, it is essential to identify the specific substance that has come into contact with the skin. Many instances of dermatitis are of “occupational” origin, arising from exposure to substances encountered in the workplace, as seen in professions such as:
- Hairdressing
- Painting
- Construction and chemical industries
Bacterial or fungal infections, particularly those caused by Staphylococcus and Streptococcus, are more likely to occur when the skin is already compromised by abrasions, often representing a complication of pre-existing dermatitis.
For endogenous dermatitis, a combination of genetic, immunological, and environmental factors is implicated. Additionally, psychosocial stress is recognized as a significant contributor to the development of dermatitis.
In summary, the causes of dermatitis can be categorized into the following types: allergic, irritant, infectious, genetic-immunological, and stress-related.
Risk Factors
Common risk factors for dermatitis include:
- Exposure to chemicals such as detergents, soaps, solvents, and herbicides
- Bacterial, viral, fungal, or parasitic infections
- Allergies to specific substances (e.g., dust, mold, animal dander, medications) or foods
- Alterations in immune response
- Psychosocial stress
Symptoms of Dermatitis
Despite the various types and origins of dermatitis, the predominant symptom is pruritus, often accompanied by the formation of small vesicles filled with serous fluid that may rupture and lead to crusting.
The intensity of itching can be severe, significantly impacting the quality of life for individuals affected by dermatitis, potentially resulting in insomnia, loss of appetite, and irritability. Scratching may lead to skin lesions, facilitating the entry of pathogenic microorganisms.
The primary symptoms of dermatitis include:
- Pruritus
- Erythema
- Vesicles/Crusts
- Xerosis
- Edema
- Desquamation
Diagnosis and Treatment of Dermatitis
Diagnosis typically involves a comprehensive medical history, along with specific tests of the skin, blood, or both. In certain cases, a biopsy may be warranted. The diagnosis is primarily based on the clinical presentation, the appearance of the skin, and the affected areas.
It is also crucial to ascertain whether the individual has used any medications, encountered irritants, or has known allergies or infections. Identifying the underlying cause is essential for determining the appropriate treatment.
Commonly prescribed treatments include:
- Moisturizing or corticosteroid-based creams
- Antihistamines to alleviate itching
- Antibiotics
- Ultraviolet phototherapy
Types and Characteristics of Dermatitis
The following are the principal types of dermatitis and their distinctive features:
- Psoriasis: A chronic inflammatory skin disease that is non-infectious and non-contagious, psoriasis affects millions and can significantly impact the lives of those affected. It typically manifests on the elbows, knees, scalp, and lower back, with onset occurring most frequently between the ages of 15 and 35. Treatment options vary based on symptom severity and may include emollients, corticosteroids, or biologic therapies. The precise etiology remains unclear, although genetic and environmental factors are believed to play a role.
- Seborrheic Dermatitis: This chronic skin condition affects both adults and children, with its causes remaining largely unknown. It is characterized by itching, erythema, and the presence of whitish, oily, or dry scales. It is non-contagious and primarily affects the face and scalp, with a higher prevalence in men and exacerbation during colder months. Treatment typically involves medicated shampoos and topical corticosteroids.
- Atopic Dermatitis: Commonly seen in children but capable of occurring at any age, atopic dermatitis, also known as atopic eczema, is characterized by pruritus and can become chronic with frequent relapses. It is associated with immune system disorders and may co-occur with other allergic conditions. Diagnosis involves a thorough personal and family history, along with symptom observation and allergy testing. Treatment focuses on hydration, avoidance of triggers, and corticosteroid use.
- Contact Dermatitis: This form of dermatitis arises from direct exposure to specific substances or allergens, leading to itching and irritation. Identifying the causative agents is essential for effective management. Common triggers include certain metals, topical medications, paints, perfumes, and chemicals. Symptoms typically include localized erythema, intense itching, and the potential for vesicle formation. Treatment generally involves topical corticosteroids and addressing the underlying causes.
