Exfoliative

Exfoliative is an adjective describing processes that involve exfoliation, the shedding or desquamation of surface cells. In medical contexts, the term is used for conditions that feature skin or mucosal shedding, for techniques that collect exfoliated cells for analysis, and for toxins or diseases that promote epidermal or epithelial shedding.

In dermatology, exfoliative processes include conditions such as exfoliative dermatitis, a diffuse scaling of the skin that can accompany drug reactions, psoriasis, or erythroderma. Other disorders involve focal or bullous desquamation, as seen in bullous impetigo or staphylococcal scalded skin syndrome, where superficial skin layers detach and peel. Exfoliative dermatitis is characterized by widespread erythema and scaling, and may require evaluation for underlying causes and potential complications.

Exfoliative toxins are produced by certain strains of Staphylococcus aureus. Exfoliative toxins A and B are serine proteases that target desmoglein-1 in desmosomes, weakening cell adhesion in the superficial epidermis and leading to loss of coherence between keratinocytes. Clinically, this can manifest as bullae and widespread skin shedding, most prominently in infants and young children but also in adults with susceptible strains.

Exfoliative cytology refers to the collection and examination of cells shed from body surfaces, rather than from a tissue biopsy. It is used in screening and diagnostic tests such as Pap smears for cervical cancer, as well as cytology of urine, sputum, and other body fluids. While less invasive than biopsy, exfoliative cytology may have limitations in sensitivity and specificity and is often followed by histopathological evaluation when indicated.

See also: exfoliation syndrome, cytology.