Lexicon for Atopic Dermatitis

This is a lexicon for Atopic Dermatitis.
Click on a letter and discover all the related terms and their definition.

  • Ichthyosiform erythroderma


    The name of a type of hereditary ichthyosis, where the skin is red and squamous all over the body. This appears from birth.
  • Ichthyosis vulgaris


    Ichthyosis is a hereditary condition affecting keratinization (formation of the epidermis). There are several types of varying severity. The most common ichthyosis, also the least severe, is ichthyosis vulgaris (vulgar meaning frequent). It begins in childhood and is manifested through dry and scaly skin, particularly on the abdomen, arms and legs. It is often described as "lizard skin" or "snake skin". The term ichthyosis actually comes from the Greek word for fish. Ichthyosis vulgaris and atopic dermatitis often affect patients together.  They have a similar genetic basis: a filaggrin deficiency. Emollient treatments are effective against Ichthyosis vulgaris.
  • IgE


    IgEs (immunoglobulins) are a type of antibody, manufactured by lymphocytes (white blood cells), most commonly in response to allergies or parasite infections. In atopic dermatitis, blood IgE is higher, but this is variable. Attempting to alter blood IgE levels, whether of total IgE or those specific to certain allergens, is not useful for treating atopic dermatitis.
  • Immediate hypersensitivity


    A variety of allergy where the clinical symptoms appear very quickly (within minutes) after the introduction of an allergen. For example, allergy to insect stings or to certain drugs. Symptoms of immediate hypersensitivity are asthmatiform dyspnea (difficulty breathing), urticaria, and shock (known as anaphylactic shock)
  • Immune system

    The mechanism that allows the body to fight infection and aggressions.

  • Immunoglobulins


    A synonym of antibodies Antibodies are proteins known as globulins. Depending on their structure they are divided into classes: IgG, IgA, IgM, IgD and IgE. IgEs are involved in some allergies. The other classes have various functions, their primary role being to protect against infection
  • Immunoglobulins E

    IgE are the antibodies involved most specifically in allergic phenomena.

  • Impetiginization


    Secondary infection of a lesion that is initially not infected. For example, atopic eczema lesions can become infected by streptococci or staphylococci, and take on the appearance of impetigo. This is known as impetiginization, and requires anti-bacterial treatment. 
  • Impetigo


    A bacterial infection, fairly common in children, which appears as small bullae (blisters) and yellowish crust. Impetigo often appears on the face. It is caused by streptococci or staphylococci, or a combination of both. Unless very minor, the treatment generally recommended is antibiotics for several days, as well as a topical treatment. 
  • Infantile seborrheic dermatitis


    A skin condition specifically affecting small infants (between 1 and 6 months) and often known as Leiner-Moussous disease. Infantile seborrheic dermatitis appears as redness on the buttocks and sometimes in skin folds, as well as particularly extensive and stubborn cradle cap. Local antiseptic treatment can result in rapid improvement. There is no link between infantile seborrheic dermatitis and atopic dermatitis.
  • Infection

    Infected skin is irritable, inflamed, red and has small yellow or red blisters on the surface. Staphylococcus aureus is the bacteria the most frequently involved in skin infection in patients suffering from eczema.

  • Infection


    Disease caused by micro-organisms, generally bacteria.
    The most common skin infections are impetigo, folliculitis, and erysipelas.  Systemic bacterial infection is known as septicemia. Infection may also be viral (herpes, shingles, chickenpox, etc.). 
  • Inflammation


    Alteration of tissue, generally accompanied by pain, redness, increase in heat in the local area, and swelling (edema). An 'inflammatory condition' is inflammation that is not caused by infection. For example, arthritis (or rheumatism), gout, etc. Atopic dermatitis and psoriasis are both chronic inflammatory diseases of the skin. 
  • Innate immunity


    Part of the immune system that reacts to antigens without needing to recognize them specifically. Thus, innate immunity acts instantly, and is the first line of defense. The skin contains many elements of innate immunity: Toll-like receptors (TLRs) which recognize aggressors, peptides (small proteins) that have natural antibiotic properties, Langerhans cells which present antigens to lymphocytes, which in turn react by producing specific antibodies for each antigen.
  • Insomnia


    Insomnia, and more generally difficulty sleeping, are one of the worst effects of the pruritus associated with atopic dermatitis. Patients who sleep poorly often have trouble paying attention (at school or work), and this can have an impact on their personal lives. Sleeping problems are one of the symptoms measured by the SCORAD. Improvement of this symptom is a major goal of treatment.
  • Interferons


    Cytokines involved in immunological reactions. Their name is due to the first of their properties to be discovered: they interact with viral infections.
  • Interleukines


    Interleukines are a type of cytokine. They are molecules of the immune system that transmit signals or instructions from one cell to another (this is the etymology of the word interleukine). There are more than 20 interleukines, called IL-1, IL-2, etc...
    In atopic dermatitis, an excess of interleukines that act in sync with TH2 lymphocytes (type 2 T-helpers) has been observed (such as IL-4, IL-5, and IL-13). Practically speaking, there is no treatment available that specifically targets the interleukines that affect atopic dermatitis.  
  • Intradermal tests


    An intradermal injection is made with a very small, fine needle, that is inserted into the dermis, that is a superficial injection. The liquid can be seen lifting the skin. In atopic allergy tests, allergens are injected intradermally. They can also be made to penetrate the skin after first piercing it with an implement, which is known as a prick test. 
  • Intrinsic


    Intrinsic is the opposite of extrinsic, and means "without the involvement of external factors". Some researchers have attempted to distinguish between extrinsic atopic dermatitis (caused by allergies) and intrinsic atopic dermatitis (with no allergic cause). This distinction has no practical impact.
  • Involucrin


    An important molecule in the formation of the epidermis, a phenomenon known as keratinization. Involucrin helps corneocytes (cells of the stratum corneum) to become solid, and thus reinforces the epidermis' barrier function.
  • Irritation dermatitis


    Secondary inflammation on contact with certain substances that are poorly tolerated by the skin. Most often this includes surfactants such as soaps and detergents. Irritation dermatitis causes redness, desquamation, and burning sensations. In principle, and in contrast to eczema, which is an allergic dermatitis, there should be no pruritus or vesicles. Occupations which require exposure to irritants should take precautions against this (wearing gloves, using gentle cleansing products, etc). 
    Atopic patients with fragile or inflamed skin are particularly vulnerable to irritation dermatitis.
    Irritation dermatitis leaves the skin vulnerable and can therefore facilitate allergic contact eczema.  
  • Itch mites


    Small skin parasites that cause scabies, an incredibly pruritic condition (severe itching). Scabies is easy to cure.
  • Itching


    Itching is a sensation that provokes a patient to scratch, and is often relieved by scratching. The medical term is pruritus, a synonym of itching. Itching or pruritus is the primary symptom of atopic dermatitis. Itching is an important factor in all scales measuring the severity of atopic dermatitis.