TOW #49: Tuberculosis screening

We are fortunate to live in an increasingly diverse city with many immigrants from around the world. At this time of year we see more families planning their summer travel to visit family members abroad, so this is a good time to think about how to screen them for TB after traveling. Materials for this week:

Key take-home points:

  1. What are the rates of TB in the US and what are the risk factors among children? TB has been declining in the US and reached an historic low of 3.2 cases per 100,000 in 2012. The biggest risk is being born outside the US or traveling to another country, especially for >1 week, and staying with family. For children, additional risks include living among family members or visitors born in endemic countries, or living with high risk adults, including those affected by homelessness, incarceration, drug use or HIV. Those with chronic diseases, immunodeficiency, and/or using high-dose steroids are also at higher risk of developing TB.
  2. Who do we need to screen in clinic? It’s recommended to start screening for latent TB infection (LTBI) from the first time we meet patients and annually at well visits, or 10 weeks after return from travel (although considered acceptable to wait for annual check-up). To assess LTBI risk factors, there are 4 validated questions: 1) Has a family member or contact had TB? 2) Has a family member had a positive TB test? 3) Was the child born in a high-risk country (i.e., outside US, Canada, Australia, New Zealand or Western Europe)? 4) Has child traveled to a high-risk country for more than 1 week? (and SCH ID team add: or has child had household visitors from a high-risk country?)
  3. Which screening tests do we use? Screening tests vary by age group: tuberculin skin test (TST or PPD) is still preferred for children less than 5. Interferon gamma release assays (IGRAs, including QuantiFERON -TB Gold) measure interferon-gamma response to mycobacterial antigens. IGRAs are now the preferred test for ages 5 and older as they are relatively specific to M. tuberculosis, do not require return visit, and are not cross-reactive with BCG vaccine. We can use both tests to help establish diagnosis when there are indeterminate results, or concern for false positives or negatives.
  4. What happens if there is a positive TB screen? To establish a diagnosis of latent TB, rule out active disease through a chest x-ray, history and exam. The initial preferred treatment for positive latent TB is with isoniazid (INH) for 9 months (there are alternative schedules to this based on special patient needs).
  5. How common is BCG vaccine? How does BCG vaccine affect interpretation? Bacille Calmette -Guerin (BCG) immunization is widely used in TB endemic countries; the WHO estimates that 83% of the world’s population has received this vaccine. Most countries recommend giving the vaccine at birth, and the majority of children receive it before age 5. Because of the varying effects of BCG on interpreting TB tests, we use a conservative approach and BCG status is not used in interpreting PPD reactions. Quantiferon gold testing is not affected by cross-reactivity with BCG.

TOW #48: Menstrual disorders

As we help with the process of puberty, addressing the challenges that arise with menarche and menstrual disorders in adolescents is a common issue we see in primary care. For those of you who have had your adolescent rotation, this is a great topic for you to facilitate.

Materials for this week:

Take-home points for this week:

  1. How is the menstrual cycle different for adolescents than fully mature females? In adolescents the hypothalamic-pituitary-ovarian (HPO) axis feedback loops are not yet mature. For the first 1-2 years after menarche, steroid hormones do not yet regularly have coordinated negative and positive feedback loops to cause ovulation, so menstrual cycles may be anovulatory or infrequent /irregular (oligoovulation). In the first year after menstruation, ~50% of cycles are anovulatory. One of the most difficult aspects of these cycles for teens is that they can cause prolonged and/or unpredictable bleeding.
  2. What's considered a "normal" cycle for a teen? AAP and ACOG define normal menstrual cycles for adolescents as having an interval of 21–45 days with the duration of flow lasting <=7 days, and average product use of 3-6 pads/tampons per day. We should be concerned when there's heavier bleeding (soaking through products after 1-2 hours), cycles >90 days apart for even one cycle, or a change from regular to very irregular.
  3. What defines "abnormal uterine bleeding (AUB)"? Bleeding that's heavy or prolonged or occurs outside normal menstrual cycles. Ovulatory AUB, or heavy menstrual bleeding, occuring as part of the usual cycle, is most commonly caused by uterine problems (i.e., endometrial polyps, leiomyomas, malignancy) or bleeding disorders. Ovulatory dysfunction is AUB that presents as irregular, heavy, or frequent episodes of bleeding without a clear pattern. While this is usually from anovulatory cycles, it's considered a diagnosis of exclusion; other causes to consider would be endocrine disorders, pregnancy and infection.
  4. When working up AUB, what are key parts of the history and physical? In addition to regular elements of H&P, we should obtain 1) Menstrual history: timing of menarche, usual frequency, duration, and volume of bleeding, presence of menstrual cramps, when/how did menstrual bleeding change, and any medical problems or lifestyle changes or other events that coincided with the change; 2) confidential HEADSSS review of substance use, sexuality, sexual activity, exposure to STIs, contraception, and any history of sexual abuse; 3) related ROS including symptoms of PCOS, thyroid disease, bleeding disorders, pelvic infection, anemia, psychosocial dz like eating disorders/female athlete triad; and 4) physical exam including external genitalia; consider a full pelvic exam in sexually active females.
  5. What tests would you obtain? Depending on the presentation, appropriate lab testing could include a urine pregnancy test or quantitative hCG level, CBC, TSH, and iron studies. If there's heavy bleeding, check coagulation studies including von Willebrand panel and possibly platelet function. An androgen panel would be useful if a patient is hirsute or has significant acne. An ultrasound would be done to help evaluate pelvic anatomy, uterine abnormalities and endometrial thickness – usually it could be done transabdominally, but transvaginal can provide better anatomy if patient is sexually active and more detail is needed.

TOW #47: Abnormal head size and shape

An important aspect of evaluating infant growth is head size and shape. Positional plagiocephaly has increased with back to sleep recommendations, and treatment continues to evolve, in part thanks to research by some of our local craniofacial experts.

Materials for this week:

Take-home points for assessing abnormal head size and shape, especially plagiocephaly:

  1. Clinical definitions: Newborns have 7 skull bones separated by 6 major sutures important to skull growth: 1 metopic, 2 coronal, 1 sagittal, and 2 lambdoid. Craniosynostosis is defined as premature fusion at one or more of the cranial sutures, resulting in restriction of skull growth at that site. Unilateral flattening over the occiput is due to either positional plagiocephaly or lambdoid suture craniosynostosis.
  2. Epidemiology: During the first two years of life, 75% of head growth occurs; only 25% occurs after age two. About 20% of infants have positional plagiocephaly in the first 4 months, which increased with 1992 “back to sleep” guidelines. Craniosynostosis affects 1 in 1800. Lambdoid synostosis affects 3 in 100,000.
  3. Physical exam: Look at the head from multiple angles, especially from the top. Positional plagiocephaly has a “parallelogram” shape with the ipsilateral ear pushed forward and ipsilateral bossing with no palpable ridge. Lambdoid synostosis is distinguished by a trapezoid shape with ipsilateral ear pulled back and contralateral bossing with a palpable ridge over the suture.
  4. Work-up: Generally clinical exam is most important so follow head size and shape closely. If concerned, refer locally to craniofacial clinic to decide on imaging.
  5. Management: Provide patient education about position, including changing direction baby is facing in the crib, keeping babies out of “containers” (carseats, swings, etc.) and promoting tummy time. Refer to PT for any concerns of decreased mobility or torticollis. Refer to craniofacial around 5-6 months if not improving. Helmet therapy costs about $2000 and may not be covered by insurance. It is usually implemented between 6-9 months. Follow developmental status closely as plagiocephaly is associated with higher rates of developmental delay at 36 months.