2. Disorders of skin color Dr. Kejian Zhu Sir Run Run Shaw Hospital http:www.srrsh.com

3. diseases of hypo(de)pigmentation diseases of hyperpigmentation

4. diseases of depigmentation vitiligo

5. outline hypopigmentated patches (leukoderma) melanocytes are reduced or lost Pathogenesis is not clear Autoimmunity against melanocytes or melanin is thought to be associated with the occurrence Topical steroids and PUVA are useful treatments

6. classification Vulgaris: Focal: localized Generalized: multiple, usually symmetrical, less than 50% of body area Universal: widespread, more than 50% of body area Acral: hand and foot Segmental: leukoderma paralleled to cutaneous nerves

7. Clinical features 1-2% of the population Men and women at the age about 20 1-2% familial cases Complete leukoderma, sharply circumscribed Slight increase in pigmentation at the periphery of the eruptions Irregular in shape and size Often coalesce Gray hair around the leukoderma, white hair in the leukoderma asymptomatic

8. symmetrical involvement universalfocalgray and white hair

9. treatment Topical and oral PUVA therapies and topical steroids are the first-line treatments Leukoderma on the face and fingers can be concealed by special cosmetics Narrowband UVB exposure Surgical interventions TCM

10. diseases of hyperpigmentation chloasma

11. Clinical features Also named as melasma Occur in women in their 30s or older, rare in men Sharply demarcated light to dark brown patches on the face Irregular in size and shape Aggravated by UVR in summer and subsides in winter Pregnancy may trigger the onset asymptomatic

12. dark brown macular pigmentation Butterfly-like macule

13. pathogenesis Not clear Abnormalities in sex hormones (estrogen ) and adrenocortical hormones Autoimmune hyperthyroidism Drugs: chlopromazine, phenytonium, spironolactone, et al.

14. treatment Discontinue the causal factors, such as artificial sex hormones Protection from UVR Topical hydroquinone (2-5%) and tretinoin Oral or intravenous vitamin C Q-switched Nd:YAG laser TCM