White Addison's disease: What is the possible cause?

A case of chronic primary adrenal insufficiency without hyperpigmentation i n a 64-year-old woman is reported. Due to the absence of hyperpigmentation the diagnosis was delayed and she became critically ill. During endocrine e valuation, in order to investigate the mechanism responsible for the absenc e of hyperpigmentation, skin biopsy was done and hormones responsible for t he skin pigmentation were measured. Absence of hyperpigmentation is explain ed by high degree of melanosome degradation in secondary lysosomes called " compound melanosomes", which overwhelmed increased stimulation of the skin pigmentation. Melanocyte-stimulating hormones were elevated with a striking ly high beta-LPH/ACTH ratio. To our knowledge, this is the first study of p athogenic mechanisms responsible for the absence of hyperpigmentation in wh ite Addison's disease. (C) 1999, Editrice Kurtis.