National Physical Therapy Examination (NPTE) Practice Exam

Which of the following best defines cellulitis?

1. An infection of the dermis and subcutaneous tissue

2. The presence of dried fragments of sloughed dead epidermis

3. The presence of a dermal or subcutaneous solid and elevated lesion

4. Inflammation of the dermis

The correct answer is: An infection of the dermis and subcutaneous tissue

Cellulitis is best defined as an infection of the dermis and subcutaneous tissue. This condition typically arises when bacteria, often stemming from a cut, scratch, or other breach in the skin, invade these deeper layers. The infection leads to red, swollen areas on the skin, which may feel warm and tender. It is essential to recognize that cellulitis affects both the dermis—the layer of skin beneath the outermost layer—and the subcutaneous tissue, which consists of fat and connective tissue. Understanding this definition helps to distinguish cellulitis from other skin conditions. For instance, the presence of dried fragments of sloughed dead epidermis relates more to conditions like necrosis or crusting rather than an active infection. Similarly, a dermal or subcutaneous solid and elevated lesion describes a different issue, such as a nodule or cyst, which does not necessarily imply an infection. Lastly, while inflammation of the dermis can occur in various dermatological conditions, it does not specifically address the infective nature nor the depth of tissue involved in cellulitis. Therefore, recognizing that cellulitis encompasses both an infection and its localization to the dermis and subcutaneous tissue is crucial for accurate identification and treatment.