Letters to the Editor
Diagnosing Patients with Suspected Thyroiditis
TO THE EDITOR: Thank you for the article on thyroiditis in the May 15, 2006, issue of American Family Physician (AFP).1 I would like to comment on Figure 1 in the article, an algorithm for the diagnosis of suspected thyroiditis. The authors suggest that the question "Is the patient postpartum?" should be answered at a key decision point. Based on a "yes" answer to that question, combined with low thyroid-stimulating hormone and high radioactive iodine uptake levels, the suggested diagnosis is Graves' disease.
The implication here is that Graves' disease only affects postpartum women. As noted in another feature in the same issue, Graves' affects adult women primarily, with a female-to-male incidence ratio of at least 5:1, and may occur sporadically in adolescent females.2 Based on the autoimmune nature of Graves' disease, pregnancy could certainly play a role. However, other etiologies may include genetic susceptibility, stress, and high iodine intake. A recent prospective cohort study demonstrated smoking to be an independent risk factor for Graves' in women.3 A previous issue of AFP offered an alternate algorithm for diagnosing hyperthyroidism.4 Family physicians should not exclude a diagnosis of Graves' disease in a patient with hyperthyroidism simply because she (or he) is not postpartum.
Author disclosure: Nothing to disclose.
REFERENCES
1. Bindra A, Braunstein GD. Thyroiditis. Am Fam Physician 2006;73:1769-76.
2. Leung AK, Pacaud D. A swelling in the neck [Photo Quiz]. Am Fam Physician 2006;73:1793-4.
3. Holm IA, Manson JE, Michels KB, Alexander EK, Willett WC, Utiger RD. Smoking and other lifestyle factors and the risk of Graves' hyperthyroidism. Arch Intern Med 2005;165:1606-11.
4. Reid JR, Wheeler SF. Hyperthyroidism: diagnosis and treatment. Am Fam Physician 2005;72:623-30.
in reply: Graves' disease most commonly affects women of reproductive age, and the majority will have the onset of the condition when they are not pregnant. Some patients with preexisting Graves' disease will improve during pregnancy, only to experience an exacerbation in the postpartum period when the immunosuppressive effects of pregnancy are gone. Other women will have the initial onset of Graves' disease in the postpartum period. When a woman presents with hyperthyroidism during the year following a pregnancy, it is important to differentiate between Graves' disease and the more common postpartum thyroiditis because the therapies for each condition differ. For this reason, we emphasized the postpartum period in Figure 1 of our article, which was an algorithm for the diagnosis of suspected thyroiditis.1 The text of our article provides clinical and imaging clues to allow the physician to make the correct diagnosis.1
REFERENCES
1. Bindra A, Braunstein GD. Thyroiditis. Am Fam Physician 2006;73:1769-76.
Methods for Diagnosing Peripheral Vascular Disease
TO THE EDITOR: In the article "Peripheral Vascular Disease: Diagnosis and Treatment"1 in the June 1, 2006, issue of American Family Physician, Dr. Sontheimer indicated that if peripheral vascular disease is suspected, physicians should screen patients using the ankle-brachial index (ABI) in one or both extremities. In my experience, busy physicians rarely take the time to measure an ABI in the office, because this is usually not a reimbursed procedure. It is time consuming and expensive to refer a patient with suspected peripheral vascular disease to a hospital vascular laboratory for Doppler determination of ABI. Thus, many patients in the early stages of this disease may go undiagnosed and untreated.
A recent study demonstrated oscillometry to be a simpler and faster method for determining ABI in the office setting.2 Oscillometry is the automated method of measuring blood pressure that is utilized in most home blood pressure monitors. As the blood pressure cuff deflates, the oscillometer reports the greatest fluctuation in pulse-to-pulse pressure as the systolic pressure. The determination of ankle and brachial pressures by this method is a valid alternative to measuring ABI using Doppler.
The researchers in this study measured ABI by automated oscillometry and Doppler ultrasound in 201 patients, including 55 patients with peripheral arterial disease.2 They reported a correlation coefficient of 0.78 between methods in left and right legs; the mean ABI difference between methods was 0.04 ± 0.01 and 0.06 ± 0.01, respectively, in the left and right legs. They concluded that automated oscillometry is a reliable and easier way to measure ABI.2
I have tried this method in my own practice in patients whom I suspect have peripheral vascular disease. It only takes moments to move the arm cuff to the same-size part of the lower leg and push the button to automatically record the ankle systolic pressure. If the ankle pressure is equal to, or higher than, the brachial pressure determined by the same method, the ABI is normal. Conversely, an ankle-to-brachial pressure ratio significantly lower than 1 should prompt further diagnostic testing and referral.
Author disclosure: Nothing to disclose.
REFERENCES
1. Sontheimer DL. Peripheral vascular disease: diagnosis and treatment. Am Fam Physician 2006;73:1971-6.
2. Beckman JA, Higgins OH, Gerhard-Herman M. Automated oscillometric determination of the ankle-brachial index provides accuracy necessary for office practice. Hypertension 2006;47:35-8.
Send letters to Kenny Lin, M.D., Assistant Editor, American Family Physician, e-mail: afplet@aafp.org. Letters submitted via regular mail should be sent to: 11400 Tomahawk Creek Pkwy., Leawood, KS 66211-6272.
Please include your complete address, telephone number, fax number, and e-mail address. Letters should be fewer than 500 words and limited to one table or figure and six references (including citation of original article). Please submit a word count.
Letters submitted for publication in AFP must not be submitted to any other publication. Possible conflicts of interest must be disclosed at time of submission. Submission of a letter will be construed as granting the American Academy of Family Physicians permission to publish the letter in any of its publications in any form. Letters will be edited to meet style and space requirements.
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