How Is Eczema Diagnosed? A Helpful Guide from EAA

How is eczema diagnosed?

Eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition characterised by itchy, red, and sometimes scaly or oozing rashes. Accurate diagnosis is essential for effective management. Many people wonder how is eczema diagnosed, especially when symptoms overlap with other skin conditions. Doctors use a combination of clinical evaluation, medical history, and selective testing to confirm the condition and rule out other skin disorders. In some cases, referral to a dermatologist or allergist is necessary to optimise both diagnosis and treatment.

Medical history

A detailed personal and family medical history is a critical component of diagnosis. Many individuals with atopic dermatitis also have other atopic conditions such as asthma, hay fever, or food allergies. A family history of eczema or other allergic diseases increases the likelihood of the diagnosis. Clinicians consider symptom onset, pattern, severity, and potential environmental or dietary triggers to distinguish eczema from other skin conditions.

Clinical examination

Physical examination allows the doctor to evaluate the appearance, distribution, and severity of the rash. Signs often include chronic or severe itch, erythematous (red) patches, scaling, oozing, and evidence of an “itch-scratch cycle,” where scratching damages the skin barrier and worsens itching. Age-specific patterns are also considered: infants often have eczema on the cheeks and scalp, while older children commonly develop rashes in the creases of elbows and knees.

Diagnostic tests

Understanding how is eczema diagnosed helps individuals and families seek appropriate care and avoid delays in treatment. While eczema is primarily diagnosed clinically, selective tests may be used to identify triggers or rule out other conditions. Allergy testing, such as skin prick tests or serum IgE measurements, can detect sensitivities to environmental allergens like pollen, dust mites, mould, or pet dander. Patch testing may help identify allergens responsible for allergic contact dermatitis, a subtype of eczema. Blood tests are usually not required for diagnosis but can be used to evaluate coexisting allergies. In rare cases, a skin biopsy may be performed to confirm the diagnosis or exclude other disorders.

Diagnostic criteria

Alongside history and examination, doctors use standard criteria to diagnose eczema. Key indicators include chronic or severe itching, rashes that differ in colour from surrounding skin, scaly or oozing lesions, evidence of an itch-scratch cycle, and age-specific patterns and locations.

Differential diagnosis

Doctors also distinguish eczema from other conditions with similar appearances. Examples include:

• Contact dermatitis: An acute rash caused by direct contact with chemicals or irritants; can develop at any age.

• Psoriasis: An immune-mediated condition often developing in adulthood; rashes may be covered with silvery scales.

• Seborrheic dermatitis: Skin rashes tend to be oily, yellow, and crusty, often affecting the scalp and face; “cradle cap” is a common form in infants.

• Tinea corporis (ringworm): A fungal infection common in children; causes circular, scaly rashes that may resemble eczema.

Knowing how is eczema diagnosed allows for earlier intervention, better symptom control, and improved quality of life. By using a combination of history, physical examination, selective testing, and comparison with other skin conditions, doctors can accurately diagnose eczema and develop an appropriate treatment plan. Early diagnosis and intervention allow healthcare providers to tailor management strategies, reduce flare-ups, and improve quality of life for patients.