Hypopigmentation of skin

Generalised absence of skin pigmentation is seen in Albinism 

Following are the syndromes with albinism

Chediac higashi syndrome also called as phagocytic deficiency disease

Phenylketonuria a condition characterised by inborn error of metabolism

Patchy absence of skin pigmentation may be due to Vitiligo which is seen in 

• Idiopathic cases
• Autoimmune disease
• Thyroid disease
• Pernicious anemia

In the presence of vitiligo always rule out immune causes in that patient

What are the causes of Hypopigmented Lesions

• Early vitiligo
• Leukoderma-early
• Hansen's disease
• Nevus anemicus
• Leafy macules-tuberous sclerosis
• Tinea versicolor
• Pityriasis alba

Circumscribed hypopigmented lesions of the skin may be seen in Hansens disease ( Tuberculoid or Borderline Tuberculoid types) and Tinea versicoior.