Carpal Bone Ossification


The carpal bone ossify aka turn into bone aka magically become visible on an x-ray in a predictable order.

The easiest way to remember is that it starts at the capitate (smack dab in the middle) and then goes in a ulnarly-directed spiral. I was going to say “clockwise” or “counter-clockwise” but that would depend on which side of which hand you were looking at. So capitate, followed by hamate and then down to triquetrum and so on. Except for the pisiform, being a sesamoid bone it gets left behind and only develops years later.

  1. Capitate: 1-3 months
  2. Hamate: 2-4 months
    1. Distal radius: 1 year
  3. Triquetrum: 2-3 years
  4. Lunate: 2-4 years
  5. Scaphoid: 4-6 years
  6. Trapezium: 4-6 years
  7. Trapezoid: 4-6 years
    1. Distal ulna: 5-6 years
  8. Pisiform: 8-12 years

I included the distal radius and distal ulna in there for good measure.

I know I could have been fancier with changing the length of the metacarpals or their growth plates, but it was more fun to make the animated gif.

Streptococcal Pharyngitis


Sore throats (pharyngitis) are a common complaint in primary and emergency care settings. Most of the time, pharyngitis is caused by viral infection (most commonly rhinovirus).

Streptococcus pyogenes, aka Lancefield group A streptococci, (GAS) is the most common bacterial cause of pharyngitis. The possible complications of GAS infection include:

  • Rheumatic fever
  • Post-streptococcal glomerulonephritis
  • Peritonsillar/retropharyngeal abscess
  • Otitis media
  • Mastoiditis
  • Pediatric autoimmune neuropsychiatric disorder associated with Group A streptococci (PANDAS) *controversial!

Signs and symptoms

GAS pharyngitis may also include fever, chills, malaise, headache, nausea, vomiting, abdominal pain, or maculopapular rash (scarlet fever). Cough, coryza/rhinitis, and conjunctivitis are uncommon symptoms for GAS pharyngitis. However, clinically diagnosing GAS pharyngitis based on history and physical is incredibly unreliable, so patients with a convincing presentation would benefit from laboratory confirmation (i.e., throat culture, rapid antigen detection test of throat swab). The Centor and McIsaac criteria are useful for helping rule out GAS pharyngitis, but shouldn’t be used exclusively to diagnose it.

The Centor criteria are scored based on the presence of:

  1. Fever (subjective or >38 C)
  2. Lack of cough
  3. Tender lymphadenopathy (anterior cervical)
  4. Tonsillar exudate

The MacIsaac criteria add an extra point for patients < 14 years old (since this age group is more prone to GAS pharyngitis) and subtract a point if >45 years old. A low score on these criteria help to exclude GAS pharyngitis, but higher scores indicate a need for lab tests.

The first-line treatment for GAS pharyngitis is penicillin. Other antimicrobial agents vary between different guidelines. Guidelines vary about whether empiric treatment should be considered before lab results have confirmed a diagnosis.


  • Aalbers J et al. 2011. Predicting streptococcal pharyngitis in adults in primary care: A systematic review of the diagnostic accuracy of symptoms and signs and validation of the Centor score. BMC Medicine: 9;67.
  • Kociolek LK, Shulman ST. 2012. Pharyngitis. In: Annals of Internal Medicine: In the Clinic (Cotton D, Taichman D, Williams S, Eds.). ITC3-1.
  • Weber R. 2014. Pharyngitis. Primary Care Clinics in Office Practice: 41;91.
  • Wessels MR. 2011. Streptococcal pharyngitis. New England Journal of Medicine; 364:648.
  • Worrall G. 2011. Acute sore throat. Canadian Family Physician: 57;791.

Pierre-Robin Sequence


Pierre-Robin Sequence is not a syndrome, it’s a sequence. While it is a collection of features, one happens because of the one that came before.

The features are:

  • Retrognathia/micrognathia (posterior mandible or very small mandible)
  • Glossoptosis (downwards/posterior displacement of the tongue due to the small mandible
  • Airway obstruction (because the tongue is in the way)

Pierre-Robin Sequence is associated with cleft palate (50% of children with the sequence have cleft palate). There are two proposed theories:

  1. The first is that the tongue simply gets in the way of the palate from fusing
  2. The second is that the tongue prevents the newly fused palate from staying fused (this is currently the more popular theory)

PRS, though not a syndrome itself, is associated with multiple syndromes including Stickler Syndrome, velocardiofacial syndrome, fetal alcohol syndrome and Treacher Collins Syndrome.

PHACE Syndrome (hemangiomas)

PHACE_syndromeThere are no shortage of congenital syndromes that are acronyms arranged into some sort of vaguely pronounceable word. There will be lots of doodles about these, but we’ll start off with a more uncommon one – PHACE Syndrome.

PHACE Syndrome is a collection of findings that go along with large infantile hemangiomas. They’re the more worrisome (but less obviously disfiguring) things you need to look for when you see a baby with a large hemangioma on the face or multiple hemangiomas.

  • Posterior fossa brain malformations
  • Hemangiomas
  • Arterial anomalies
  • Cardiac anomalies and coarctation of the aorta
  • Eye abnormalities
  • Sternal cleft

The most common symptom of PHACE is cerebrovascular abnormalities, followed by cardiac anomalies (coarctation, aortic arch anomalies, VSDs). If you suspect PHACE, do clinical exam of the skin and eyes and MRI of the head, neck and chest.

Other cool facts

  • PHACE occurs in full-term normal birth weight infants (other hemangiomas tend to occur in preterm infants)
  • Quite common, more girls than boys (8:1)
  • Don’t confuse it with Strurge-Weber (port wine stain, associated with the facial dermatomes)
    • Port wine stains don’t proliferate and then regress like an infantile hemangioma

Approach to Primary Amenorrhea


Primary Amenorrhea is defined as the absence of menses:

  • By age 13/14 without normal development of secondary sexual characteristics; OR,
  • By age 15/16, with normal secondary sexual characteristics.

In contrast, Secondary Amenorrhea refers to a loss of menses after it has already been established.

The causes of amenorrea are myriad, with an important one being pregnancy.

Causes of Amenorrhea
Hypothalamus Stress, malnutrition, exercise, lactation, immaturity, Kallmann syndrome
Pituitary Tumor, empty sella, apoplexy, hyperprolactinemia/prolactinoma
Ovaries Gonadal dysgenesis, premature ovarian failure, menopause, ovarian tumor, polycystic ovarian syndrome (PCOS), ovarian enzyme deficiency, chromosomal abnormalities (e.g., 45XO)
Uterus Intrauterine scarring, cervical agenesis, androgen insensitivity
Outflow Tract Imperforate hymen, transverse vaginal septum, cervical stenosis, Mullerian agenesis
Thyroid Hypo/hyperthyroidism
Other Constitutional delay of puberty, hyperandrogenism, Cushing’s syndrome, medications

The most common pathologic causes of Primary Amenorrhea are:

  • Chromosomal abnormalities: 50%
  • Hypothalamic abnormalities: 20%
  • Mullerian agenesis: 5%
  • Pituitary abnormalities: 5%

Determining the etiology of Primary Amenorrhea depends on careful history-taking and a targeted physical exam. Key points to address in the history include:

  • Potential for pregnancy, current lactation
  • Develop of secondary sexual characteristics
    • On a side note, the general order of female sexual development is: breasts, pubic hair, growth spurt, menses; or, “boobs, pubes, grow, flow”
  • Lifestyle factors such as stress, nutrition, exercise, weight changes
  • Medication: THC, antipsychotics, or irradiation
  • Associated symptoms:
    • Hyperprolatinemia: galactorrhea
    • Hyperandrogenism: hair loss/excess, acne, voice change
    • CNS tumor: headaches, visual field deficits, polyuria/polydipsia
    • Family history: Does everyone have relatively late puberty?

In terms of physical exam:

  • Vitals, height, weight
  • Secondary sexual characteristics: breasts, pubic/axillary hair
  • Thyroid: exopthalmos, goiter, abnormal deep tendon reflexes
  • Hyperandrogenism: hirsuitism, acne, hair loss
  • Hypercortisolemia: striae, hyperpigmentation
  • Turner syndrome: webbed neck, low hair line, widely-spaced nipples, short stature
  • Pelvic exam: hymen, vaginal septum, ultrasound for uterine anatomy

Laboratory investigations can offer lots of insight:

  • βHCG: Gotta rule out this common reason first!
  • TSH, PRL: To test for hypo/hyperthyroidism and hyperprolactinemia.
  • LH, FHS: For practicality’s sake, these would probably be ordered at the same time as TSH, PRL.
  • +/- Androgens (testosterone, DHEAS, 17-alpha-hydroxyprogesterone): May indicate PCOS or androgen-secreting tumor, androhen insensitivity syndrome, or 5-alpha-reductase deficiency.
  • +/- Estradiol: These assays lack sensitivity, standardization, and only capture a single time point.

Since chromosomal abnormalities account for half of the pathologic cases of Primary Amenorrhea, karyotyping will be useful for patients who are found to have abnormal uterine anatomy on ultrasound or have elevated FSH, LH. Patients with an absent uterus may be worked-up for abnormal Mullerian development (46XX karyotype and normal female testosterone levels) versus a deficit in masculinization (i.e., androgen insensitivity syndrome, 5-alpha-reductase deficiency). There is a normal uterus, and LH and FSH are high, that means there is nothing feeding back to stop their release; karyotype may reveal Turner syndrome (45XO), while normal karyotype (46XX) may indicate Mullerian agenesis.

The over all treatment goals are to:

  • Treat underlying cause:
    • Lifestyle
    • Discontinue offending medications
    • Surgery
  • Preserve fertility
  • Reduce risk of complications (e.g., remove undescended tests in androgen insensitive patients to mitigate cancer risk).
  • Master-Hunter T, Heiman DL. 2006. Amenorrhea: evaluation and treatment; 73:1374.
  • The Practice Committee of the American Society for Reproductive Medicine. 2008. Current approach to amenorrhea. Fertility and Sterility;90:S219.
  • Welt CK, Barieri RL. Etiology, diagnosis, and treatment of primary amenorrhea. In: UpToDate (Eds: Snyder PJ, Crowley Jr WF, Kirkland JL). Accessed 2013.05.05.

Maculopapular Childhood Rashes



A kid without a rash just isn’t a kid.

Chicken Pox

  • Incubation: 10-21d, infective until crusted over
  • Rash: vesicles on macules (dewdrops on rosepetals),
  • Very pruritic!
  • Other symptoms: 1-3d prodrome of fever and respiratory symptoms
  • Treatment: supportive, acyclovir for severe disease, VZIG for post-exposure prophylaxis
  • Complications: 1st or 2nd trimester = congenital varicella syndrome


  • Incubation: 5-15d
  • Rash: pink macules and maculopapules, starts on neck.
  • Non-pruritic!
  • Other symptoms: HIGH FEVER, cough, respiratory symptoms, erythematous pharynx, tonsils & TMs
  • Treatment: supportive
  • Complications: febrile seizures
  • * Generally affects kids <5 years old


  • Incubation: 10-14d, dx with measles IgM
  • Rash: maculopapular, starts on face.
  • Non-pruritic!
  • Other symptoms: the 3 Cs
    • 1) Cough 2) Coryza (runny nose) 3) Conjunctivitis
    • Koplik spots in mouth 1-2d before rash
  • Treatment: supportive, prophylactic Ig
  • Complications: secondary bacterial infection, encephalitis (1:1000), subacute sclerosing panencephalitis (1:100000)

Rubella aka German Measles

  • Incubation: 14-21d, infective 5d before rash and 7d after
  • Rash: pink maculopapular, starts on face.
  • Pruritic!
  • Other symptoms: non-specific
  • Treatment: supportive
  • Complications: congenital rubella syndrome (very bad*), first four months of pregnancy highest risk (this is why we check rubella immunity status in prenatal screening)

* Congenital Rubella Syndrome
“Blueberry muffin baby” (purpura). Cataracts/congenital glaucoma, congenital heart disease, hepatosplenomegaly, jaundice, microcephaly, developmental delay

Fifth Disease aka Erythema Infectiosum

  • Incubation: 4-14d, infective prior to onset of rash
  • Rash: slapped cheeks (raised uniform maculopapular lesions on cheeks), may appear on extensor surfaces
  • Usually not pruritic
  • Other symptoms: flu-like illness ~3d prior to rash
  • Treatment: supportive, blood transfusions if aplastic crisis
  • Complications: arthritis (10%), vasculitis
    • Aplastic crisis: reticulocytopenia, not bad in normal people, very bad anemia if you already have chronic hemolytic anemia
    • During pregnancy: fetal hydrops/fetal loss

* This is a good one to actually know the virus name! PARVOVIRUS B19

Other rash descriptors to think about

  • Sandpaper rash: scarlet fever (Group A Strep), they also have strawberry tongue, fever and sore throat
  • Pink macules with central clearing: erythema marginatum (one of the major Jones criteria for rheumatic fever)
  • Palpable purpura: Henoch-Schonlein Purpura
  • Non-blanching petechiae: BAD (meningococcal disease), could be other things too, but need to rule out meningitis

Signs of Meningitis

Meningitis is very literally inflammation of the meninges. Something swollen in a closed space is never good, so it’s important to not miss meningitis when it presents.

Classic triad of meningitis

  1. Fever
  2. Neck stiffness
    • Brudzinski
    • Kernig
  3. Mental status change – in babies this can be an increase in somnolence or irritability (unconsolably crying)

Important organisms:

  • Bacterial
    • Listeria*
    • E. coli*
    • GBS (Group B strep)*
    • Neisseria meningitidis
    • Strep pneumoniae
    • Staph aureus
    • Gram neg bacilli
    • Haemophilus influenza
  • Viral (“aseptic”)
    • HSV
    • Enterovirus
    • HIV
    • Mumps

* These are the common ones in the neonatal period


  • Positive Gram stain
  • CSF white blood cell (WBC) count >1000/uL with a predominance of neutrophils
  • Low CSF glucose concentration <40 mg/dL (2.2 mmol/L)
  • Empiric treatment: high doses of a 3rd generation cephalosporin (cefotaxime, ceftriaxone) and vancomycin (this covers antibiotic-resistant S. pneumoniaeN. meningitidis, and Hib)

Kawasaki Disease

Kawasaki Disease is one of the pediatric rashes that you always need to have in the back of your mind. Most of the time the disease is self-limiting, but the consequences of not catching it are pretty bad (turns out coronary artery aneurysms often lead to things like infarction and DEATH).

Warm CREAM is an unrelated (and somewhat unpleasant) mnemonic to help remember the signs and symptoms of Kawasaki. The “warm” is a fever (one lasting more than 5d) and then you need 4/5 of the other criteria (non-purulent conjunctivitis, rash, palmar erythema/swelling, cervical adenopathy, dry and red mucous membranes, the infamous strawberry tongue). The kid doesn’t need all 4 as he or she is sitting in front of you, but the presentation and the history combined should include those criteria.

Treatment is with high doses ASA and IVIG, you do this to prevent the sequelae of coronary artery aneurysms and myocarditis, and it’s best to get an echo to check up on things.

Acyanotic vs Cyanotic Congenital Heart Defects

You separate congenital heart defects into acyanotic and cyanotic. Basically, is the baby (or kid) nice and pink, or is he or she dusky as they like to say. Sometimes the blueishness only happens when they’re working really hard, like feeding and crying (or thinking about the pathophysiological mechanisms of heart disease).

One of the important things to remember is that acyanotic heart defects can switch over if they’re left alone for too long because of pulmonary hypertension caused by the extra flow. This is called Eisenmenger Syndrome.

It’s also important to realize that many of the cyanotic lesions are duct dependent, meaning that as long as the ductus arteriosus is open, they are happy and pink. The problems start in that time 6-24h after delivery when the ductus closes. Thankfully you can keep it open by giving prostaglandin E1.

Need the ductus for systemic circulation:

  • Coarctation of the aorta
  • Critical aortic stenosis
  • Hypoplastic left heart syndrome

Need the ductus for pulmonary circulation:

  • Pulmonary atresia
  • Critical pulmonary stenosis
  • Tricuspid atresia
  • Tetralogy of fallot

Also, I realize that the 5 Ts of cyanotic heart lesions are a pentad of 6 (plus some), but mnemonics can only do so much, and the T thing is just so catchy.

For a more detailed illustration of PDAs, you can check out this doodle!

Hand, foot and mouth syndrome (coxsackie virus)

Hand, foot and mouth syndrome (or disease to all you lay people out there) is a common viral illness, most often caused by coxsackie virus. Generally it affects daycare-aged children (the 1-10ish age group), mostly under the age of 6. The big thing is the fever with a rash on, you guessed it, the palms, soles and in the mouth. Sometimes the rash can also present on the trunk or back as well. The worst part is that the vesicles in the mouth are VERY painful, so it’s not uncommon for kids to want to stop eating or drinking when they have it.

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