Thyroxine unmasks Addison's disease.
Patients with primary hypothyroidism may also have other underlying associated endocrinopathies, which are important to exclude. A 15-y-old girl presented with clinical biochemical evidence of hypothyroidism.


CONCLUSIONS
Thyroxine replacement unmasked Addison's disease and precipitated an acute adrenal crisis. On physiological steroid replacement therapy, her "hypothyroidism" resolved.
Shaikh
M G
MG
Department of Endocrinology, Birmingham Children's Hospital, Birmingham, United Kingdom. guftar.shaikh@bch.nhs.uk
Lewis
P
P
Kirk
J M W
JM
D000224:Addison Disease / Q000150:complications* / Q000175:diagnosis*; D000293:Adolescent; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000150:complications* / Q000188:drug therapy; D013974:Thyroxine / Q000627:therapeutic use
D013974:Thyroxine