Chronic leg rash in Graves disease, not always pretibial myxedema
Pawan Pusalkar, Jenny Tringham & Emma Bingham
We describe a case of 38 year old female of Indian origin who presented with symptoms of Graves disease to our clinic. She had a diffusely enlarged goitre and minimal eye signs. Her T4 was 62 pmol/L(924), T3 9 pmol/L(3.56.5), and TSH was <0.01 mu/L (0.35.0). Radioactive iodine uptake scan revealed the presence of increased uptake throughout the gland. She was treated with carbimazole for 18 months and is in remission at present.
About 12 months ago she reported as having a lesion in both her shins which was pigmented and itchy. This was diagnosed as pretibial myxedema in the endocrine clinic and a dermatology opinion was sought. This was as an ill defined patch with some raised areas over the left shin measuring about 18×10 mm. Most of the patch was hypopigmented with some areas of hyperpigmentation. Differential diagnosis was between lichen simplex or pretibial myxedema. A 4 mm punch biopsy was carried out.
Histology revealed the diagnosis to be sarcoidosis, although skin tuberculosis was suggested as another possibility to be ruled out. Her Chest X ray was normal as was her ESR, serum ACE, calcium and Montoux test.
This case highlights an association between sarcoidosis and Graves disease. In one series of 111 patients with sarcoidosis in Italy 3 patient had Graves disease, 4 had clinical hypothyroidism (all female) and 2 had papillary carcinoma(1).
In another series 19.2%(15 out of 89) of patients with sarcoidosis attending pulmonary clinics in Sweden had clinical or serological evidence of endocrine autoimmunity. Thyroid autoimmunity was the most common among these patients(2). This link should be kept in mind when treating thyroid disorders and also in someone with sarcoidosis.
1. Antonelli A, Fazzi P, Fallihi P, Ferrari SM & Ferrannini E. Chest 2006 Aug 130(2) 526532.
2. Papadopoulos KI, Hornblad Y, Liljebladh H & Hallengren B. Eur J Endocrinol 1996 March 134(3) 331336.