Arms and Legs Hypopigmentation

Areas of hypopigmentation on the arms and legs

The commonest conditions causing hypopigmentation at these sites include vitiligo,Pityriasis versicolor and post inflammatory either after liquid nitrogen or surgery to skin cancers.Post inflammatory hypopigmentation is also seen with discoid lupus erythematosus.Localised morphea or lichen sclerosus can also present as hypopigmented patches but the underlying skin will be firm in morphea.Undertreated psoriasis or eczema of the trunk may also present as hypopigmented patches but some evidence of these conditions elsewhere should allow you to make the diagnosis.In white populations idiopathic guttate hypomelanosis due to chronic sun damage commonly causes hypopigmented areas on the lower legs and forearms.

In the newborn look for the ashleaf macules of Tuberous sclerosus or pale connective tissue nevi.Segmental vitiligo may also be seen congenitally.Nevus depigmentosus and nevus anaemicus may also present as hypopigmented patches in this age group.

Management   Scrape if scaly to confirm pityriasis versicolor.Biopsies are generally unhelpful in this presentation.The diagnosis is made by clinical skill and knowledge.Lack of sensation in the centre of a white patch should raise the diagnosis of tuberculoid leprosy

SIGN DIP MEN   Overview of Hypopigmentation

 

S-Squamous    Healing areas of eczema and psoriasis,Pityriasis alba,Pityriasis versicolor,Post discoid lupus erythematosus scarring,Tinea corporis,

 

I-Infective    Pityriasis versicolor,Tuberculoid Leprosy,Pinta,Syphilis,Post herpes zoster

 

G-Granulomatous   Sarcoidosis,

 

N-Neoplastic    Morpheic Basal cell skin cancer,Epidermodysplasia verruciformis,

 

D-Drugs     Phenols,

 

I-Immunological    Vitiligo,Halo nevi,Localised Morphea,Lichen sclerosus,Scleroderma,

 

P-Physical     Following liquid nitrogen,Post traumatic in dark skin,Idiopathic guttate hypomelanosis,Chronic radiodermatitis,

 

M-Metabolic

 

E-Endocrine

 

N-Nutritional

 

Other Localised congenital depigmentation  Nemonic is (WANT A DIP) of colour.

Wardenberg's,Alezandreni,nevus anaemicus,nevus depigmentosus,Tuberous sclerosus,Dyskeratosis congenita,Incontinentia pigmenti achromicans,Piebaldism.

 

Others- Genetic Albinism,Piebaldism,Klein Wardenburg syndrome,Voigt-Koyanagi syndrome,Ashleaf macules of Tuberous sclerosus,Nevus depigmentosus,Nevus anemicus,