Letters to the editor

Letters to the editor

Calcaneal Ultrasonography for Bone Assessment

TO THE EDITOR: The article, “Radiologic Bone Assessment in the Evaluation of Osteoporosis,” (1) was an excellent review of the subject. However, I question the logic used to formulate the authors’ algorithm in Figure 4 for assessing bone mineral density in women.

Discordance in bone mass measurements refers to the significant differences that can be found in bone density at various skeletal sites. Discordance is more prevalent in early postmenopausal women and becomes less of a problem as women age. Several studies (2) in women 50 to 59 years of age have shown that 8 to 12 percent are normal or osteopenic at one site, but osteoporotic at another site. This is not surprising considering that the composition and metabolism of bone varies from site to site. Early postmenopausal bone loss, mainly caused by estrogen deficiency, will affect the cancellous skeleton first and would be expected to be manifested initially at a central site (lumbar spine). (3) In persons who are more than 65 years of age, bone density varies less between different skeletal sites, and peripheral measurements, such as calcaneal ultrasonography, will accurately reflect the condition of the skeletal areas of most concern (the hips and spine).

In my opinion, the author has gotten it backwards. Calcaneal ultrasonography is more helpful, not less helpful, in patients over 65 years of age. Conversely, I would be hesitant to reassure a woman who is early postmenopausal that her risk of spinal fracture is low based on a normal calcaneal ultrasonography, knowing that the chance this result is a false-negative is approximately 10 percent. Because dual-energy x-ray absorptiometry (DXA) scanning of central sites is readily available in my community at a reasonable cost, I do not order peripheral bone mass determinations in women under 65 years of age. In rural communities, this technology may be less readily available and peripheral bone mass measurements may need to be used to assess early postmenopausal women. A positive (osteoporotic) peripheral measurement would be highly predictive of low bone mass at the spine or hip. However, a negative (normal) calcaneal ultrasonography would not rule out the possibility of significant osteoporosis at a central site.

MICHAEL C. WULFERS, M.D.

Cape Girardeau Physician Associates

Cape Girardeau, MO 63703

REFERENCES

(1.) Brunader R, Shelton DK. Radiologic bone assessment in the evaluation of osteoporosis Am Fam Physician 2002;65:1357-64.

(2.) Miler PD. The challenges of peripheral bone density testing. J Clin Densitom 1999;1:211-7.

(3.) Miller PD, Bonnick SJ. Clinical application of bone densitometry. In: Favus MJ, ed. Primer on the metabolic bone diseases and disorders of mineral metabolism. 4th ed. Philadelphia, Pa.: Lippincott, Williams & Wilkins; 1999:152-9.

IN REPLY: We appreciate the opinion of Dr. Wulfers. Many areas in the management and screening of osteoporosis remain uncertain. The vast majority of patients who will require therapy for osteoporosis are over 65 years of age. Only DXA allows for serial measurements to assess the efficacy of therapy. For patients under 65 years of age who do not have any risk factors for osteoporosis, we believe that calcaneal ultrasound is adequate for screening. While discordancy exists between central and peripheral bone sites, the majority of clinically relevant discordancy requiring therapy will be in patients over 65 years of age and in those under 65 years of age who have risk factors. We do not disagree with Dr. Wulfers about the limitations of a modality such as calcaneal ultrasound. However, to advocate calcaneal ultrasound in those with the greatest risk of developing fractures but consider it inappropriate for the lowest risk group, is a position we would disagree with.

Finally, we prefer DXA to calcaneal ultrasound because of its ability to assess central bone mass and to conduct serial measurements. However, the cost for DXA is higher, and no study that we are aware of has shown that DXA scanning is more predictive of fracture risk than calcaneal ultrasound.

RICHARD BRUNADER, M.D.

DAVID SHELTON, M.D.

22623 Indian Springs Rd.

Salinas, CA 93908

Vitamin D as a Risk Reduction Factor for Colorectal Cancer

TO THE EDITOR: The article, “Recent Developments in Colorectal Cancer Screening and Prevention,” (1) was good but overlooked one important risk reduction factor for colorectal cancer: vitamin D. Cohort (2,3) and ecologic (4) studies have shown that serum vitamin D–or solar ultraviolet-B (UV-B) radiation (280-320 nm), which photoinitiates the production of vitamin D–is a significant risk reduction factor for colon cancer and at least 10 other types of cancer. (4) Serum 25-OH vitamin [D.sub.3] was found to be inversely associated with the incidence of colorectal adenoma in a large cohort study (5) of nurses among those with consistent vitamin D intakes during the past 10 years. Vitamin D affects calcium metabolism as well as reducing the proliferation of colon cancer cells. (6)

While an analysis (4) did not consider factors other than solar UV-B radiation at the surface at 500 locales in the United States, studies in progress include such potentially confounding factors as urban/rural residence, Hispanic ethnicity, diet (calcium, energy, fat, fiber, protein, and vitamins A, C, and E intake per capita), smoking, and socioeconomic status. For colon cancer, solar UV-B radiation and rural residence (another ecologic surrogate for vitamin D production) accounted for 41 and 51 percent of the variance in mortality rates in women and men, respectively, from 1970 to 1994; fiber accounted for 21 percent (inverse), and vitamin A accounted for 8 percent of the variance for men, in general agreement with the literature.

Vitamin D or its metabolites are not always confirmed as a risk reduction factor for colorectal adenomas or carcinoma; this may be related to the interval between exposure or measurement and disease outcome. Colon cancer is believed to take 10 to 20 years to proceed from initiation to mortality, and vitamin D and its metabolites may be important in certain stages in the process and not in others.

WILLIAM B. GRANT, PH.D.

12 Sir Francis Wyatt Place

Newport News, VA 23606-3660

CEDRIC F. GARLAND, DR.P.H.

Department of Family and Preventive Medicine

University of California, San Diego

9500 Gilman Drive, 0631C

La Jolla, CA 93093

REFERENCES

(1.) Pignone M, Levin B. Recent developments in colorectal cancer screening and prevention. Am Fam Physician 2002;66:297-302.

(2.) Garland CF, Garland FC, Gorham ED. Calcium and vitamin D. Their potential roles in colon and breast cancer prevention. Ann N Y Acad Sci 1999;889:107-19.

(3.) Freedman DM, Dosemeci M, McGlynn K. Sunlight and mortality from breast, ovarian, colon, prostate, and non-melanoma skin cancer: a composite death certificate based case-control study. Occup Environ Med 2002;59:257-62.

(4.) Grant WB. An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet-B radiation. Cancer 2002;94:1867-75.

(5.) Platz EA, Hankinson SE, Hollis BW, Colditz GA, Hunter DJ, Speizer FE, et al. Plasma 1,25-dihydroxy- and 25-hydroxyvitamin D and adenomatous polyps of the distal colorectum. Cancer Epidemiol Biomarkers Prev 2000;9:1059-65.

(6.) Tangpricha V, Flanagan JN, Whitlatch LW, Tseng CC, Chen TC, Holt PR, et al. 25-hydroxyvitamin D-1 alpha-hydroxylase in normal and malignant colon tissue. Lancet 2001;357:1673-4.

EDITOR’S NOTE: A copy of this letter was sent to the author of “Recent Developments in colorectal cancer screening and prevention,” who declined to reply.

Managing Asthma Should Not Focus on Dust Mite Control

TO THE EDITOR: We were surprised to see such a heavy emphasis placed on dust mite control in the article, “Environmental Control of Allergic Diseases.” (1) Two Cochrane reviews (2,3) conclude that the evidence for a clinically significant benefit of dust mite control efforts (e.g., fewer reduced activity days or days lost from school, rather than small changes in spirometric parameters) is, at best, limited. Given the substantial expense and effort involved in dust mite reduction efforts (many studies have provided fresh linens and house cleanings for participants because many people simply will not stick with such intensive regimens on their own), routinely recommending dust mite control can hardly be considered “benign.” Efforts to control asthma would be better spent increasing the use of anti-inflammatory medications by the substantial numbers of patients with persistent asthma who are not currently using controller medications.

BARRY G. SAVER, M.D., M.P.H.

MARK P. DOESCHER, M.D., M.P.H.

Department of Family Medicine

University of Washington

Box 354696

Seattle, WA 98195-4696

REFERENCES

(1.) German JA, Harper MB. Environmental control of allergic diseases. Am Fam Physician 2002;66:421-6.

(2.) Gotzsche PC, Johansen HK, Burr ML, Hammarquist C. House dust mite control measures for asthma (Cochrane Review). Cochrane Database Syst Rev 2002;3:CD001187.

(3.) Sheikh A, Hurwitz B. House dust mite avoidance measures for perennial allergic rhinitis (Cochrane Review). Cochrane Database Syst Rev 2002;3: CD001563.

IN REPLY: We appreciate the comments of Drs. Saver and Doescher. While it is certainly true that anti-inflammatory medications have been shown to help patients with asthma, our article (1) focused on the effects of environmental control measures on allergic disease, and we did not intend to compare these measures with other treatments. The Cochrane reviews (2,3) concluded that more studies are needed to determine the benefit of environment control on asthma and allergic rhinitis symptoms. A large trial is currently under way for asthma. The data for allergic rhinitis are limited, but the Cochrane review included one study that showed that simple interventions, such as using mattress covers and washing bedding every two weeks to control dust mite exposure, may be beneficial. We believe that using dust mite covers on mattresses and pillows as well as washing bedding every one to two weeks are reasonable, inexpensive measures that should be recommended to patients with asthma until better data are available for guidance.

JEFFREY A. GERMAN, M.D.

MICHAEL B. HARPER, M.D.

Department of Family Medicine

Louisiana State University Health Science Center

1501 Kings Highway

Shreveport, LA 71130

REFERENCES

(1.) German JA, Harper MB. Environmental control of allergic diseases. Am Fam Physician 2002;66:421-6.

(2.) Gotzsche PC, Johansen HK, Burr ML, Hammarquist C. House dust mite control measures for asthma (Cochrane Review). Cochrane Database Syst Rev 2002;3:CD001187.

(3.) Sheikh A, Hurwitz B. House dust mite avoidance measures for perennial allergic rhinitis (Cochrane Review). Cochrane Database Syst Rev 2002;3: CD001563.

Guidelines for Proper Use of Child Safety Seats

TO THE EDITOR: We would like to commend Dr. Biagioli on the excellent article, “Proper Use of Child Safety Seats.” (1) However, some clarification of issues regarding the most recent guidelines for best practices is needed.

Dr. Biagioli correctly explains the benefits of keeping infants rear-facing until they weigh 20 lb and reach one year of age. However, the benefits do not stop for children who are over one year of age and 20 lb. Guidelines from the American Academy of Pediatrics (2) state that a child in a convertible seat can remain rear-facing until they reach the upper weight limit of the seat (30 to 35 lb), provided the top of their head remains at least one inch below the top of the child restraint. While the child’s feet may touch the vehicle seatback, this is not a problem unless it causes excessive discomfort for the child. For parents concerned about the potential risk of leg injury, an appropriate response is that broken legs heal more easily than broken necks. We have both kept our children rear-facing until 30 lb (at age 20 months and 24 months, respectively). In addition, the recommended 45-degree angle for rear-facing child restraints applies only to small infants so they can maintain an open airway. For older infants and toddlers, a more upright seat provides superior crash protection.

Children in forward-facing seats may outgrow the height of the shoulder harness slots before they exceed the weight limits, since the harness slots must be at or above the shoulders in a forward-facing configuration. In addition, most older vehicles can be retrofitted with anchors for use with an upper tether strap; parents should consult their vehicle owner’s manuals for instructions on how to take advantage of this additional safety feature.

We disagree with Dr. Biagioli’s recommendation against low-back boosters. While they are inappropriate for use in vehicles without headrests or high seatbacks, they are an excellent choice when the vehicle seat or headrest can offer the child head and neck protection in rear impacts. They also have the advantage of being less conspicuous than high-back boosters, which may be more acceptable to an older child. Their smaller size may allow installation of three child restraints in the rear seats of small vehicles, and facilitate use when carpooling. In addition, low-back boosters are usually inexpensive. However, shield boosters, which are somewhat similar in design to low-back boosters, are no longer recommended as acceptable child restraint systems.

Finally, we would like to recommend that children be evaluated for graduation to a vehicle seatbelt alone using the posture and belt fit guidelines of the SafetyBeltSafe five-step test described at www.carseat.org. The height, weight, and age limits published by the National Highway Traffic Safety Administration (3) are based on a limited number of vehicles and children, and are not absolute rules. A child may need a booster in a vehicle with a long seat cushion, but not in a vehicle with smaller seats where they can comfortably sit up straight and achieve good belt fit.

KATHLEEN DESANTIS KLINICH, M.S.

MIRIAM MANARY, M.S.E.

University of Michigan Transportation Research Institute

2901 Baxter Road

Ann Arbor, MI 48109-2150

REFERENCES

(1.) Biagioli F. Proper use of child safety seats. Am Fam Physician 2002;65:2085-90.

(2.) American Academy of Pediatrics. Car safety seats: a guide for families 2002. Elk Grove Village, IL: American Academy of Pediatrics, 2002. Retrieved January 2003, from the World Wide Web: www. aap.org/family/carseatguide.htm.

(3.) Klinich KD, Pritz HB, Beebe MS, Welty KE. Survey of older children in automotive restraints. Stapp Car Crash Conference proceedings, Society of Automotive Engineers. Report No. SAE 942222. Warrendale, Pa, 1994.

IN REPLY: I would like to clarify two items from my article, “Proper Use of Child Safety Seats.” (1) In March 2002, the Committee on Injury and Poison Prevention for the American Academy of Pediatrics (AAP) changed their recommendation on how long to face a child’s car seat rearward. The AAP policy statement still recommends that “children should face the rear of the vehicle until they are at least (one) year of age and weigh at least 20 (lb).” (2) This is consistent with my article (1); however, the updated policy also recommends that “if a car safety seat accommodates children rear facing to higher weights, for optimal protection, the child should remain rear facing until reaching the maximum weight for the car safety seat, as long as the top of the head is below the top of the seat back.” (2) Therefore, providers should recommend that parents check the limits of their seat and that a child face rearward as long as possible.

The article (1) states that “low-back boosters are not recommended,” but this information applies only to low-back shield boosters. There are other models of low-back boosters that employ the use of a lap and shoulder belt that are safe and inexpensive. To protect the head, back, and neck, providers should advise that low-back boosters only be used in an automobile seat that has a headrest and a shoulder-lap combination belt.

FRANCES BIAGIOLI, M.D.

Oregon Health & Science University

4411 SW Vermont St.

Portland, OR 97219

REFERENCES

(1.) Biagioli F. Proper use of child safety seats. Am Fam Physician 2002;65:2085-90.

(2.) American Academy of Pediatrics. Selecting and using the most appropriate car safety seats for growing children: guidelines for counseling parents. Pediatrics 2002;109:550-3. Retrieved January 2003, from the World Wide Web: www.aap.org/ policy/re0116.html.

Dermatitis Herpetiformis and a Gluten-Free Diet

TO THE EDITOR: In the article, “Autoimmune Bullous Dermatoses: A Review,” (1) one of the conditions the authors discuss is dermatitis herpetiformis. They suggest that gluten-sensitive enteropathy (celiac disease) is an associated manifestation of dermatitis herpetiformis and that a gluten-free diet is one way to treat dermatitis herpetiformis. I think dermatitis herpetiformis should rather be thought of as a variant or complication of untreated celiac disease. (2) Supporting this is the fact that dermatitis herpetiformis and celiac disease share the same human leukocyte antigen haplotype and show similar results on serum and intestinal antibody testing. Typical pathologic changes of celiac disease are found on small intestinal biopsy in almost 100 percent of patients with dermatitis herpetiformis. (2)

A gluten-free diet should be recommended for life in patients with dermatitis herpetiformis. Longer duration of exposure to gluten has been associated with a higher incidence of autoimmune disorders such as type 1 diabetes, connective tissue diseases, autoimmune thyroid disease, and autoimmune hepatitis. (3) Nonautoimmune complications of untreated celiac disease include osteoporosis, iron deficiency anemia and, most ominously, small intestinal lymphoma.

Silent and atypical celiac disease (dermatitis herpetiformis being an example of the latter) are now known to be common. (4) All patients with dermatitis herpetiformis should be considered to have celiac disease, and a gluten-free diet should be recommended for life.

WILLIAM LOVETT, M.D.

Tan and Chestnut Streets

Fredericksburg, PA 17026

REFERENCES

(1.) Bickle KM, Roark TR, Hsu S. Autoimmune bullous dermatoses: a review. Am Fam Physician 2002;65: 1861-70.

(2.) Fasano A, Catasi C. Current approaches to diagnosis and treatment of celiac disease: an evolving spectrum. Gastroenterology 2001;120:636-51.

(3.) Ventura A, Magazzu G, Greco L. Duration of exposure to gluten and risk for autoimmune disorders in patients with celiac disease. SIGEP Study Group for Autoimmune Disorders in Celiac Disease. Gastroenterology 1999;117:297-303.

(4.) Farrell RJ, Kelly CP. Celiac sprue. N Engl J Med 2002;346:180-8.

IN REPLY: I would like to thank Dr. Lovett for reiterating the importance of a gluten-free diet in the treatment of dermatitis herpetiformis. In Table 2 of our article, (1) we list gluten-free diet as the first treatment of dermatitis herpetiformis and indicate that sulfones (Dapsone) are beneficial for the skin lesions only. As a dermatologist, I recommend a gluten-free diet and a gastroenterologic consultation for all of my patients who have dermatitis herpetiformis. I reserve sulfones for patients who are symptomatic and want immediate relief from their pruritus.

SYLVIA HSU, M.D.

Baylor College of Medicine

Houston, TX 77030

REFERENCE

(1.) Bickle KM, Roark TR, Hsu S. Autoimmune bullous dermatoses: a review. Am Fam Physician 2002;65: 1861-70.

What Is the Most Effective Approach to Chronic Pain?

to the editor: An editorial (1) on chronic pain management in American Family Physician illustrates many of the reasons that the current management of this heterogeneous disorder is so unsatisfactory. Reflecting the common tendency to think of chronic pain as a single entity requiring a single approach to treatment, the editorial’s text begins with an estimate from the National Center for Health Statistics that “32.8 percent of the U.S. general population has persistent or chronic pain symptoms.” (1)

Such survey data do not provide a precise indication of how many of those persons have trivial discomfort that most people would ignore, how many have moderate pain that can be self-treated adequately with over-the-counter analgesics, how many have pain that can be managed effectively under a physician’s care, and how many have truly disabling pain. Surveys of this type do not discriminate adequately between patients with life-threatening diseases (e.g., disseminated cancer), those with benign but painful disorders amenable to objective diagnosis (e.g., postherpetic neuralgia), and those with less tangible conditions such as fibromyalgia. It is difficult to imagine truly effective pain care that ignores this differentiation.

Consistent with established trends in the treatment of pain in the United States, the management section of the Marcus editorial (1) focuses primarily on opioid treatment and indications for referral. Psychosocial factors are briefly mentioned but deserve more attention. There is incomplete but increasingly persuasive evidence that renewed attention to human thought and behavior is a key feature in effective management of chronic pain. Almost every issue of Pain features at least one paper supporting the hypothesis that psychosocial factors are important in the genesis and persistence of pain behavior. (2,3) Family physicians are trained in the biopsychosocial model of medicine and are a natural choice to lead research in this area.

The current research also sheds light on another urgently needed area of clinical inquiry: the etiology of chronic pain behavior. The poor prognosis for functional improvement once the disorder is firmly established indicates that there needs to be more longitudinal research on ways to prevent chronic pain as well as detect and treat it at earlier stages. Here again, family medicine should be taking the lead.

ROBERT D. GILLETTE, M.D.

32 Audubon Lane

Poland, OH 44514

REFERENCES

(1.) Marcus DA. Managing chronic pain in the primary care setting [Editorial]. Am Fam Physician 2002; 66:36,38,41.

(2.) Gillette RD. Comment on Thompson E.N; PAIN 82 (1999):109-110. Pain 2000;85:523-4.

(3.) Walsh DA, Radcliffe JC. Pain beliefs and perceived physical disability of patients with chronic low back pain. Pain 2002;97:23-31.

Send letters to Jay Siwek, M.D., Editor, American Family Physician, 11400 Tomahawk Creek Pkwy., Leawood, KS 66211-2672; fax: 913-906-6080; e-mail: afplet@aafp.org. Please include your complete address, telephone number, and fax number. Letters should be submitted on disk, double-spaced, fewer than 500 words, and limited to one table or figure and six references. 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 AAFP permission to publish the letter in any of its publications in any form. The editors may edit letters to meet style and space requirements.

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