q146 - sami2004

[ArchivalUser]

What is the answer for this Qs

[ArchivalUser]

BDAE.

[ArchivalUser]

The correct answer is B. This is a classic presentation
of Graves disease. The family history, the symptoms
and signs of hyperthyroidism (especially the diffusely
enlarged goiter with a bruit), and the exophthalmos
are all typical. Conjunctival infection is also frequently
noted. Answer A is unlikely. Viral thyroiditis can cause
hyperthyroidism and a goiter, but the thyroid gland is
usually tender. Also, viral thyroiditis will likely not last
4 months, but is usually self-limited to a few weeks.
Anaplastic carcinoma is a devastating disease with a
dismal prognosis: the thyroid gets very large very
quickly, but the disease does not present with hyperthyroidism.
A hyperactive adenoma and surreptitious
ingestion of thyroid hormone would not cause a goiter
or exophthalmos

The correct answer is A. Graves disease is an autoimmune
process, and lymphocytes in the thyroid gland
itself are responsible for a large amount of the thyroid
autoantibodies produced. Although several types of antibodies
can be tested, antithyrotropin receptor antibody
is the most specific. Antithyrotropin receptor antibody
is found in 80% to 95% of patients with Graves disease
and in essentially no other condition (although it may
be elevated in 10% to 20% of those with other forms
of autoimmune thyroiditis). Antithyroglobulin antibodies
(answer B) are found in Graves disease, autoimmune
thyroiditis, some patients with type 1 diabetes,
and in up to 20% of the general population. Antithyroid
peroxidase antibody (answer C) is elevated in
Graves disease, autoimmune thyroiditis, type 1 diabetes,
some pregnant patients, etc.

The correct answer is A. There is no need to wait before
starting propylthiouracil (PTU) or the alternative
methimazole (Tapazole), which block production of thyroid
hormone. PTU is a better choice in those with significant
symptoms because it will also partially block the
peripheral conversion of T4 (inactive) to T3 (active
form). Propanolol is helpful for controlling the symptoms
of hyperthyroidism (tachycardia, tremor, etc).
Iodine will provide further substrate for the body in the
production of thyroid hormone and should not be given
unless a thyroid-blocking agent has been started. Iodine
is useful during thyroid storm to prevent the release of
stored thyroid hormone, but it is given one hour after
PTU or methimazole. Radioablation is used for patients
who prove refractory to medicine or have poor compliance.
Thyroidectomy is rarely used for Graves in current
medical practice because of the ease and efficacy of
radioactive iodine administration (except in the case of
pregnancy and a few other unusual cases).

The correct answer is E. All of the above are known
side effects of antithyroid drugs (thioamides). Granulocytopenia
occurs in about 0.5% of patients and is a
sudden, idiosyncratic reaction. Classically, patients
present with a severe sore throat. If you have a
patient on PTU with a sore throat, check a CBC.
Aplastic anemia may occur but is rare. For these reasons,
patients starting these medications should have a
baseline CBC. Mild, transient elevation of the liver
transaminases is common, and the drug should be discontinued
if the level is greater than three times normal.
Both PTU and methimazole cross the placenta
and will inhibit the fetal thyroid, increasing the risk for
congential hypothyroidism. The risk to a fetus posed
by the drugs is less than the danger posed by a mother
with accelerating hyperthyroidism, so the medications
should be used even during pregnancy if indicated.
PTU is regarded as slightly safer in pregnancy.
Nonetheless, you should use the smallest dose possible.
If a pregnant patient is not controlled with PTU,
consider surgical thyroidectomy.

[ArchivalUser]

Can I know the source of this Q, Sami? In US I131 radioablation is the ist line treatment for graves in young pt's who have no CIs to its use.