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Fast Five Quiz: Dermatitis
Atopic dermatitis is a chronic, pruritic inflammatory skin condition that typically affects the face (cheeks), neck, arms, and legs but usually spares the groin and axillary regions. Although dermatitis improves in most patients, the condition can have a significant impact on quality of life and often creates a financial burden.
Among the various forms of dermatitis, allergic contact dermatitis is a delayed type of induced sensitivity (allergy) that results from cutaneous contact with a specific allergen to which the patient has a sensitivity. Irritant contact dermatitis is a nonspecific, nonallergic response of the skin to direct chemical damage from a corrosive agent that releases mediators of inflammation predominantly from epidermal cells.
Are you familiar with key aspects of dermatitis, including best practices for diagnosis and treatment? Refresh and test your knowledge of this condition with this short quiz.
Incessant pruritus (itchiness) is the central and most debilitating symptom of atopic dermatitis. According to guidelines from the American Academy of Dermatology (AAD), essential features that must be present for diagnosis include pruritus and eczema (acute, subacute, chronic). Typical morphology and age-specific patterns include facial, neck, and extensor involvement in infants and children; current or previous flexural lesions in any age group; and sparing of the groin and axillary regions.
Important features seen in most cases that add support to (but are not required for) diagnosis include early age of onset, asthma, seasonal allergies, and xerosis. Associated features that support the diagnosis of atopic dermatitis but are too nonspecific include the following:
Atypical vascular responses (eg, facial pallor, white dermographism, delayed blanch response)
Keratosis pilaris, pityriasis alba, hyperlinear palms, ichthyosis
Ocular or periorbital changes
Other regional findings (eg, perioral changes or periauricular lesions)
Perifollicular accentuation, lichenification, prurigo lesions
Read more about the presentation of atopic dermatitis.
A detailed history, both before and after patch testing, is crucial in evaluating individuals with allergic contact dermatitis. Potential causes of allergic contact dermatitis and the materials to which individuals are exposed should be included in patch testing. Evaluation of allergic contact dermatitis requires a much more detailed history than most other dermatologic disorders.
Women with lichen sclerosus et atrophicus frequently develop allergic contact dermatitis, complicating the severe chronic vulvar dermatosis. Patch-testing these patients may provide important information that can help in the management of recalcitrant and difficult-to-manage dermatoses.
Patients with a history of atopic dermatitis are at increased risk for nonspecific hand dermatitis and irritant contact dermatitis. They are at lower risk for allergic contact dermatitis to poison ivy.
Individuals with allergic contact dermatitis typically develop dermatitis, within a few days of exposure, in areas that were exposed directly to the allergen. Certain allergens (eg, neomycin) penetrate intact skin poorly, and the onset of dermatitis may be delayed up to 1 week after exposure. A minimum of 10 days is required for individuals to develop specific sensitivity to a new contactant. The immediate onset of dermatitis after initial exposure to material suggests either a cross-sensitization reaction, prior forgotten exposure to the substance, or nonspecific irritant contact dermatitis provoked by the agent in question.
Immediate reactions (ie, visible lesions developing < 30 minutes after exposure) indicate contact urticaria and not allergic contact dermatitis. This is particularly true if the lesions are urticarial in appearance and if the skin reaction is associated with other symptoms, such as distant urticaria, wheezing, periorbital edema, rhinorrhea, or anaphylaxis.
Read more on the presentation of allergic contact dermatitis.
Rietschel and Fowler proposed the following as primary diagnostic criteria for irritant contact dermatitis:
Macular erythema, hyperkeratosis, or fissuring predominating over vesiculation
Glazed, parched, or scalded appearance of the epidermis
Healing process beginning promptly on withdrawal of exposure to the offending agent
Negative results on patch testing that includes all possible allergens
Minor objective criteria for irritant contact dermatitis include the following:
Sharp circumscription of the dermatitis
Evidence of gravitational influence, such as a dripping effect
Lower tendency for the dermatitis to spread than in cases of allergic contact dermatitis
Morphologic changes suggesting small differences in concentration or contact time producing large differences in skin damage
Read more about the presentation of irritant contact dermatitis.
According to AAD guidelines, TCIs are recommended and effective for acute and chronic treatment, along with maintenance, in both adults and children with atopic dermatitis and are particularly useful in selected clinical situations. TCIs are recommended for use on actively affected areas as a steroid-sparing agent for the treatment of atopic dermatitis.
The AAD guidelines recommend TCS for patients with atopic dermatitis that has failed to respond to good skin care and regular use of emollients alone. Various factors should be considered when choosing a particular TCS, including patient age; areas of the body to which the medication will be applied; and other patient factors, such as degree of xerosis, patient preference, and cost of medication. Twice-daily application of corticosteroids is generally recommended for the treatment of atopic dermatitis; however, evidence suggests that once-daily application of some corticosteroids may be sufficient. Proactive, intermittent use of TCSs as maintenance therapy (once or twice weekly) on areas that commonly flare is recommended to help prevent relapses and is more effective than use of emollients alone.
AAD guidelines also suggest that application of moisturizers is an integral part of treatment of patients with atopic dermatitis, because strong evidence suggests that their use can reduce disease severity and the need for pharmacologic intervention. Use of wet-wrap therapy with or without a TCS can be recommended for patients with moderate to severe atopic dermatitis to decrease disease severity and water loss during flares.
Read more about the treatment of atopic dermatitis.
TCSs are the mainstay of treatment for allergic contact dermatitis. Various symptomatic treatments can provide short-term relief of pruritus. However, the definitive treatment of allergic contact dermatitis is the identification and removal of any potential causal agents; otherwise, the patient is at increased risk for chronic or recurrent dermatitis. Online resources allow the physician to create a list of products free of allergens to which the patient is allergic.
TCSs are the mainstay of treatment, with the strength of the TCSs appropriate to the body site. For severe allergic contact dermatitis of the hands, 3-week courses of class I TCSs are required, whereas class VI or class VII TCSs typically are used for allergic contact dermatitis of intertriginous areas or the face.
Individuals with chronic allergic contact dermatitis that is not controlled well by TCSs may benefit from PUVA treatments. Psoralen is a photosensitizer that is ingested before light exposure. Narrow-band UVB phototherapy may be as effective. Light at 308 nm can also be delivered to limited chronic areas of dermatitis.
Definitive treatment of irritant contact dermatitis is the identification and removal of any potential causal agents. An inflammatory reaction from irritant contact dermatitis to an agent, such as benzalkonium chloride (eg, Zephiran), rarely needs treatment and usually resolves with cessation of exposure. Further symptomatic therapy depends on the degree of involvement and the presence or absence of secondary infection. TCSs and TIMs are of unproven use in treating irritant contact dermatitis.
Advise patients with irritant contact dermatitis to use ceramides that contain creams or bland emollients after washing hands with soap and before sleep. Recommend mild skin cleansers (eg, Aquanil, Cetaphil, Oilatum AD, Neutrogena) in place of soap on affected areas. Instruct individuals to refrain from use of inappropriate solvents (eg, gasoline) or abrasives (eg, pumice stone) to cleanse hands; these directly defat or traumatize the skin.
Read more about the treatment of allergic contact dermatitis.
This Fast Five Quiz was excerpted and adapted from the Medscape Drugs & Diseases articles Atopic Dermatitis, Allergic Contact Dermatitis, and Irritant Contact Dermatitis.
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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: William James. Fast Five Quiz: Dermatitis - Medscape - Nov 04, 2020.
posted by dermatica at
November 05, 2020
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