Atopic Dermatitis in Emergency Medicine Clinical Presentation

The hallmarks of atopic dermatitis are intense pruritus, chronic eczematous skin lesions, and epidermal thickening and hypertrophy.

The emergency physician often is the first to diagnose atopic dermatitis. The most common presentation is that of infants, usually younger than 6 months, brought in by their parents for a persistent rash. Before coming to the ED, the parents may have tried a number of over-the-counter and home remedies. Parents usually report that the rash has waxed and waned for months with a history of dry skin since birth.

Clinicians should inquire about a family history of asthma, hay fever, allergy, and other atopic diseases. Patients with pertinent medical or family history of such disease tend to have a worse prognosis.

Parents may also give a history of poor sleep or increased irritability in the patients, which is due to the desire to scratch the skin during sleep. Atopic dermatitis begins with intense pruritus, leading the patient to scratch, which results in the characteristic rash.

Atopic dermatitis typically is not associated with fever or other constitutional symptoms, and the presence of these should prompt the clinician to look for bacterial superinfection.

Atopic dermatitis is a spectrum of disease that varies in presentation, severity, and distribution. Eczema defies a simple definition as the disease has differing characteristics depending on the age of the patient and the stage of the disease course.

Lesions may be acute, subacute, or chronic, each with a characteristic appearance. Lesions from one stage can convert into another stage at any time due to processes such as manipulation, irritation, allergy, or infection. Acute lesions are intensely itchy and present as vesicles and blisters with intense redness. Subacute disease is characterized by slight-to-moderate itching, pain, stinging, burning and redness, scaling, and fissuring of the skin with a parched and scalded appearance. Chronic eczematous inflammation demonstrates thickened skin, accentuated skin lines, excoriations, and fissuring accompanying a moderate-to-intense itch.

The pattern of skin manifestations also differs across the lifespan. In infantile atopic dermatitis, pruritic, red, scaly, and crusted lesions are typically found on the extensor surfaces and cheeks or scalp, with severe cases possibly presenting with vesicles, serous exudates, or crusting. The diaper area is protected and usually spared.

See the image below.

The lesions in the childhood stage have less exudation; the skin often demonstrates lichenified plaques in a flexural distribution, commonly antecubital and popliteal fossae, volar aspect of the wrists, ankles, and neck. See the image below.

Adult eczema has a similar distribution to that in childhood atopic dermatitis but is increasingly localized and lichenified with thickened skin, increased skin markings, and excoriated and fibrotic papules.

Certain characteristic patterns are worth mentioning.

Eczema that appears as one or several coin-shaped plaques is called nummular eczema.

Plaques with prominent skin lines are referred to as lichen simplex chronicus. These lesions are characterized by intense pruritus that ceases when pain replaces itch.

Diagnosis of atopic dermatitis is made by observing representative clinical features of the disease. The Hanifin and Rajka diagnostic criteria, which consist of 4 major and 23 minor criteria has traditionally been used, but it is time consuming and not manageable. The UK working group on atopic dermatitis has the following criteria for diagnosis, which has been most extensively validated in clinical trials. ^[8] Evidence of itchy skin with 3 more of the following:

• History of skin crease involvement

• History of other atopic disease (or a history in a first-degree relative for a child younger than 4 years)

• Presence of generally dry skin within in the past year

• Symptoms in a child beginning before age 2 years

• Visible involvement of dermatitis involving flexural surfaces

Complete Hanifin and Rajka criteria

Major criteria (need 3 or more) are as follows:

• Pruritus

• Typical morphology and distribution

• Flexural lichenification in adults

• Facial and extensor involvement in infants and children

• Dermatitis - Chronically or chronically relapsing

• Personal or family history of atopy (asthma, allergic rhinitis, atopic dermatitis)

Minor criteria (need 3 or more) are as follows:

• Cataracts

• Cheilitis

• Conjunctivitis - Recurrent

• Eczema - Perifollicular accentuation

• Facial pallor or erythema

• Food intolerance

• Hand dermatitis - Nonallergic

• Ichthyosis

• IgE - Elevated

• Immediate (type I) skin test reactivity

• Infections (cutaneous)

• Dennie-Morgan infraorbital fold

• Itching when sweating

• Keratoconus

• Keratosis pilaris

• Nipple dermatitis

• Orbital darkening

• Palmar hyperlinearity

• Pityriasis alba

• White dermographism

• Wool intolerance

• Xerosis

Severity assessment

Several tools have been developed to assess the severity of atopic dermatitis. No one is considered the criterion standard, but some validated tools are listed below ^{[9, 10, 11]} :

• Eczema Area and Severity Index (EASI) - Based solely on objective clinician assessment; primarily used in clinical trials
• SCORing Atopic Dermatitis (SCORAD) - Combines objective clinician assessment and subjective patient assessment; primarily used in clinical trials
• Patient-Oriented Eczema Measure (POEM): Based solely on subjective patient assessment; may be more convenient in clinical practice
• Patient-Oriented SCORing Atopic Dermatitis (PO-SCORAD): Based solely on subjective patient assessment; may be more convenient in clinical practice

Excoriations secondary to itch predispose to infection and can be recognized by the accumulation of serum, crust, and purulent material. Development of vesicle and/or pustules in patients with known atopic dermatitis should initiate a search for bacterial or viral superinfection; appropriate antibiotics or antivirals should be started immediately. Patients with atopic dermatitis are uniquely susceptible to herpes simplex, which may occasionally progress to a Kaposi’s varicelliform eruption; physicians and patients should be particularly vigilant for this condition. This rare complication is characterized by generalized involvement, systemic toxicity, and even death. In these cases, the patient should be treated with oral acyclovir and monitored closely. Topical corticosteroids and/or occlusive dressings are best, at least temporarily, discontinued.

Exfoliative erythroderma is another rare complication, occurring in less than 1% of patients with atopic dermatitis. Exfoliative erythroderma demonstrates a marked progression caused by widespread Staphylococcus aureus or herpes simplex superinfection and can be life threatening if it is complicated by high-output cardiac failure and heat loss.

Atrophy or striae occur if fluorinated corticosteroids are used on the face or in skin folds.

Systemic absorption of steroids may occur if large areas of skin are treated, particularly if high-potency medications and occlusion are combined.