What situation can cause a person to experience a cytotoxic hypersensitivity reaction?

Rationale:

A. Cellulitis is a bacterial infection of the skin and subcutaneous tissue that can occur when a pressure ulcer breaks the skin barrier. Open wounds provide a pathway for bacteria, most commonly Staphylococcus aureus or Streptococcus species, to enter underlying tissues, leading to redness, swelling, warmth, pain, and potentially systemic infection. This makes cellulitis a common and serious complication of pressure ulcers if not treated promptly.

B. While chronic blood loss or poor nutrition can contribute to anemia, it is not a direct complication of a pressure ulcer. Anemia may be present in patients with multiple comorbidities but is not caused specifically by pressure injuries.

C. Osteoarthritis is a degenerative joint disease unrelated to pressure ulcers. While immobility from severe pressure injuries could worsen joint function, osteoarthritis is not a direct complication.

D. Diabetes is a risk factor for developing pressure ulcers due to poor circulation and impaired wound healing, but it is not caused by pressure ulcers.

Rationale:

A. An ulcer is a full-thickness loss of skin that extends through the epidermis and into the dermis, and sometimes even deeper tissues depending on severity. Ulcers often appear as open sores or cavities, which may weep fluid, bleed, or form a crust. Common causes include pressure (pressure ulcers), vascular insufficiency (venous or arterial ulcers), trauma, infection, or chronic inflammation. Clinically, ulcers can vary in size, depth, and appearance, and they are at risk for infection, delayed healing, or tissue necrosis if not properly managed.

B. A fissure is a narrow, linear crack in the skin, usually occurring in areas where the skin is dry, tight, or under mechanical stress. Examples include cracks at the corners of the mouth (angular cheilitis) or on the soles of the feet or heels. Unlike an ulcer, a fissure does not create a broad cavity and generally does not involve extensive tissue loss.

C. A pustule is a small, raised lesion filled with pus, often less than 1 cm in diameter. Pustules are commonly seen in acne, folliculitis, or bacterial infections. Pustules are superficial; the skin remains mostly intact, unlike an ulcer where tissue is destroyed.

D. A macule is a flat, circumscribed area of discoloration, less than 1 cm in diameter. Examples include freckles, flat moles, or some rashes. A macule does not involve any loss of skin tissue, bleeding, or exudate, so it is distinctly different from an ulcer.