What is the hallmark clinical manifestation of atopic dermatitis, a common type of eczema?

Explanation: Cold weather is a common trigger for exacerbating eczema symptoms, as it can cause the skin to become dry and more prone to irritation and itching.

Incorrect choices: b. Sun exposure can be beneficial for some skin conditions but is not a common trigger for eczema exacerbation.

c. High humidity may actually help improve eczema symptoms for some individuals by keeping the skin moisturized.

d. While some people with eczema may have food sensitivities, consumption of dairy products is not a common trigger for eczema exacerbation in all cases.

Explanation: A biopsy of the skin lesion is commonly used to confirm the diagnosis of eczema and rule out other skin conditions with similar symptoms.

Incorrect choices: b. Patch testing for allergies is used to identify allergens that may be triggering eczema flare-ups but is not used to confirm the diagnosis of eczema.

c. A complete blood count (CBC) is not typically used to diagnose eczema. It may be ordered to assess for secondary infections or other underlying health conditions.

d. X-ray is not useful for diagnosing eczema, as it primarily provides images of bones and internal structures. It is not commonly used in the evaluation of skin conditions.