Loss of skin pigmentation,reduction in pigmentation and increased of pigments are features of a variety of disorders or abrormality of skin color.Detailed history-taking and examination,including use of wood’s light,are required to establish the diagnosis.

Investigations will depend on the presentation.For example,microscopy of skin scrapings should be inflammation and scaling;screening for autoimmune disease may be required if vitiligo is suspected;and investigation for endocrine disease or the porphyrias may be appropriate in hyper pigmentation.

Further details of the specific conditions are included later.

Hair and nail abnormalities

Many conditions affect the skin appendages,particularly hair and nails.Nail changes may be a marker for systemic disease or a feature of certain skin conditions.