Definition

Dermatosis: ,Any skin disease especially one not characterised by inflammation.

Dermatitis: inflammation of the skin.

Macule: flat lesions defined by an area of changed color i.e area of blanchable erythema.

Papule: a raised,solid lesion<5mm in diameter.

Plaque: a lesion >5mm in diameter with a flat, plateau-like surface.

Nodule: a lesion >5mm in diameter with a more rounded configuration

Vesicles: a circumscribed, elevated lesions containing fluid,<5mm in diameter.

Bullae: a circumscribed ,elevated lesion containing fluid, >5mm in diameter.

Pustules: raised lesions containing purulent exudate.

The Z-N acid fast stain, while highly specific, is relatively insensitive.

Culture uses a nonselective egg medium,LJ or middle brook 7H10 (3-4wks). More prefered radiometric broth culture(BACTEC)

PCR detects smaller numbers of mycobacteria in clinical specimens.