Beta-melanocyte stimulating hormone levels in subjects with hyperpigmentation associated with megaloblastic anemia.

By S. J. BAKER, V. I. MATHAN AND K. ABE H YPERPIGMENTATION OF THE SKIN in Indian patients with megaloblastic anemia appears to have been first documented by Cook.1 Studies from this unit suggested that this was often associated with vitamin B12 deficiency,2’3 though more recent studies following the introduction of folic acid assays, have shown that it can also occur in some cases of pure folate deficiency, and in mixed folate and vitamin B12 deficiency.4 A similar hyperpigmentation has been reported in an African with vitamin B12 deficiency anemia5 and in an American Negro with folic acid deficiency.6 The pathogenesis of this hyperpigmentation is unknown, though its relationship to the deficiency state is clearly shown by the fact that it clears up with appropriate treatment. Although not related to hypoadrenalism,3 the hyperpigmentation often resembles that seen in Addison’s Disease of the suprarenal. Since the latter is associated with raised melanocyte-stimulating hormone ( MSH ) levels in the blood,7 one possibility was that vitamin B12 or folate deficiency in some way increased the levels of circulating MSH. This communication reports the results of MSH assays in such patients.