Your Voice

January 1, 1999

LETTERS

LETTERS

GH treatment can cause hypothyroidism

In the excellent "Growth hormone therapy: An update" (August),the authors mention that GH therapy can be associated with such adversetreatment effects as slipped capital femoral epiphysis, acceleration ofscoliosis, peripheral edema, pseudotumor cerebri, acromegaloid features,acute pancreatitis, and gynecomastia. Another noteworthy, clinically relevantadverse treatment effect is exogenous GH treatment-associated hypothyroidismin GH-deficient patients who are euthyroid biochemically before GH therapyis begun. Though the mechanism of this GH therapy-associated hypothyroidismis unclear, studies have shown that growth hormone can blunt the pituitaryresponse to thyrotropin-releasinghormone (Hintz RL et al: Growth Abnormalities:Contemporary Issues in Endocrinology and Metabolism, volume 4. New York,NY, Churchill Livingstone, 1987, pp 52 and 153).

The hypothyroidism can result in a potentially diminished height incrementresponse to the exogenous GH therapy. To avoid or lessen the likelihoodof this effect, clinicians should monitor thyroid function every six to12 months during GH therapy or if they note decreasing rates of height incrementsduring the therapy. If the serum total T4 is low, daily supplementalthyroid replacement therapy to achieve a biochemical euthyroid status willhelp the patient reach a better height incrementresponse to the GH therapy.All monitoring of a patient on exogenousGH should be done in concert witha pediatric endocrinologist.

Albert F. DiNicola, MD, Camp Pendleton, CA

The authors reply: Dr. DiNicola mentions secondary hypothyroidismthat may become evident after initiation of GH therapy in children withhypopituitarism. We appreciate his comment since we did not address thissubject in our review. As he mentions, the mechanism of the decline in thyroidhormone levels on GH therapy is not well understood, but may result in attenuationof the growth response. In our experience, individuals subject to this effectfrequently can be identified before GH therapy is begun through the thyrotropin-releasing-hormone(TRH) stimulation test, which can be administered along with GH stimulationtesting. Children with a delayed sustained thyrotropin response to TRH anda low-normal serum thyroxine level appear to be most likely to require thyroxinesupplementation, which suggests more global hypothalamic dysfunction. Itis our practice to monitor total or free thyroxine levels yearly in GH­treatedchildren.

Dorothy I. Shulman, MD , and Barry B. Bercu, MD, St. Petersburg, FL

All febrile infants don't need to be hospitalized

"Meningitis: What's new in diagnosis and management" (September)statesthat "all febrile young infants should undergo a comprehensive laboratoryevaluation for infection," including culturing of blood, urine, andcerebrospinal fluid for bacteria. I recently was part of an extensive country-wide,three-year study for PROS (Pediatric Research in Office Settings) involvinghow febrile infants from birth to 3 months of age are treated in an outpatientsetting. About 85% of our patients received only a screening blood countor urine catheterization. Few, if any, were hospitalized for a full "sepsiswork-up"; the two cultures to grow anything produced enteroviruses.

Not all febrile infants need to be hospitalized nowadays. Much has changedin the three years since I finished my residency, when "bili"babies and sepsis work-ups were routinely seen in the hospital. Now onemust take into account many other factors besides temperature in assessinga child for hospital admission--other sick contacts, activity, and feeding,for example. Children treated as outpatients are subject to close follow-up,and the parents are given strict guidelines about what to do if the child'scondition deteriorates.

Monika M. Walters, MD, Bethesda, MD

C difficile toxin and toddler's diarrhea

"Is it toddler's diarrhea?" (September) is very helpful. Idisagree, however, with the authors' contention that cultures for Clostridiumdifficile toxin "should be performed in all patients with chronic diarrhea."Since children as young as 6 months get toddler's diarrhea and both C difficileand its toxin can be found in many healthy children younger than 1year,it seems as though this test should be reserved for children who are olderthan 1 year.I would have difficulty interpreting a positive result in achild who is younger.

Paul Allen, MD, Thomasville, GA

In assessing a child for toddler's diarrhea, the authors suggest includingin the history questions about the consumption of natural herbs. With somany parents interested in herbs and other alternative medicine, I'd appreciateknowing what herbs should be considered.

Harris Lilienfeld, MD, Lawrenceville, NJ

The author replies: Dr. Allen is correct--C difficile can be foundin healthy infants. A positive C difficile toxin coupled with diarrhea,however, warrants a trial of treatment with metronidazole or vancomycinas C difficile colitis can occur in this age group. As to Dr. Lilienfeld'squestion, herbs that cause diarrhea include fo-ti, aloe, barberry, senna,kelp, pokeroot, and yellow dock.

Chris A. Liacouras, MD, Philadelphia, PA

The myth of the virginal hymen

In "A 17-year-old with mul tiple complaints: The wrath of grapes,"November's Pediatric Puzzler concerning a case of partial hydatidiform mole,the authors write: "In response to direct questioning, she again deniessexual intercourse. The genitalia are inspected and a virginal hymen isfound. There goes that theory."

It is important to remember that the adolescent hymen is estrogenizedand distensible. Tearing of the hymenal membrane with subsequent loss ofhymenal tissue frequently does not occur in adolescent and adult women whohave experienced vaginal penetration. In fact, many young women do not bleedwhen they first experience penetration, primarily because the hymen is distensible.Although loss of posterior hymenal tissue raises the issue of penetration,the history the clinician takes from the teen, combined with some healthyskepticism, is still the best bet when it comes to ascertaining the teen'ssexual activity.

Let's put this myth of the virginal hymen to rest.

JoAnn Carson Lord, MD, Hartford, CT

The author replies: In the context of this case, the likelihood of pregnancyas a possible cause of the problems dropped a notch or two when a virginalhymen was found. Nonetheless, Dr. Lord's point is well taken: Finding anintact hymen does not mean that intercourse has not taken place.

Walter W. Tunnessen, Jr., MD, Chapel Hill, NC

In honor of Emmie's birth ...

One of my closest friends and a pediatric colleague, Julie Kardos, composedthe following poem in honor of my baby's birth. I'd love to share it withother pediatricians.

Dear Emmie, May your red reflex shine
as your pupils constrict, May your Moro be equal, May your hips never click. May you never be yellow, May you gain proper weight, May your temp never rise
beyond 30 plus eight. May you never be gassy
and never spit up, May your heart never murmur, Nor your spleen tip show up. May your dimples be shallow
and your neurons run deep. And may luck, love, and
good health be yours to keep. Happy Birthday!

Naline Lai, MD, Chalfont, PA

How to give up pacifier? Never use one

I was interested in the question about giving up a pacifier in "Behavior:Ask the experts" (November). In my experience, the best way to giveup the pacifier is not to start using one. In 50-plus years in practice,I have never seen a case of pacifier deficiency, and I am convinced thatour British colleagues are smarter than we when they call this device a"dummy." Perhaps parents who give their child a pacifier get whatthey deserve when their infant doesn't want to give it up.

Warren Bosley, MD, Grand Island, NE

Quick way to remove a nasal foreign body

I've discovered a way to remove foreign bodies in the nose that neverfails and is faster and less traumatic than other methods.

I thread a number 6 rubber Foley catheter behind the foreign body, blowup the 3 mL balloon with air, and pull out the catheter and the foreignbody together. Try it; it works.

Dennis R. Gross, MD, Altamonte Springs, FL





LETTERS. Contemporary Pediatrics 1999;0:022.