The rediscovery of pharyngitis in adolescents and Arcanobacterium hemolyticum

I'm back again in the Pediatrics ward. I enjoy Pediatrics in a superlative way. Focusing in the well-being of children is my priority. I enjoy the interaction with the residents and overall the immense opportunity I have to provide teaching. The Pediatrics residents are very pleasant doctors to work with and are eager to learn and provide the best care to the children. I enjoy seeing them doing an evidence based approach to the different entities but as well using their clinical criteria to decide whether to pursue or not a diagnostic test or any given treatment.

This past couple days have been interesting. We had two adolescent patients with tonsilopharyngitis; one of them required a drainage of a peritonsilar abscess/phlegmon; the other one responded well to antibiotics alone. Based on Centor's criteria (enlarged tonsils with exudate, tender cervical lymphadenopathy, and exposure to strep throat) alone they met the clinical criteria for a strep pharyngitis and were treated as such. The patient with the most dramatic presentation with a peritonsilar abscess required intravenous steroids once. What was interesting was the choice of antimicrobials based on the physician starting the intervention; the ENT specialist chose clindamycin; the Pediatrician chose Ampicillin/sulbactam. Any of those are actually correct, and I would argue that perhaps, Penicillin would have been the best choice in any case. Regardless of antibiotic choice, both patients did very well; however, what would have been if the outcomes would have been different?

The past week was a very intense week in the academic media as Dr. Centor published a new article in Annals of Internal Medicine focusing on Lemierre's syndrome (secondary to Fusobacterium necrophorum). This is a very important article as it broadens the differential diagnosis of tonsilopharyngitis and reinforces the recognition that it can be a life-threatening disease (as its title implies "expands the paradigm"). I enjoyed pulling the PDF at the middle of the round in one of the multiple computer stations outside the patient's room and showing an Annals of Internal Medicine article to the Pediatrics residents. I need to emphasize that before we even went to the Annals website, I pimped all of them with the differential diagnosis of tonsilopharyngitis in children and then we discussed both common and uncommon causes.

I took my Pediatrics Board in 2007; the ABP has been giving increased importance to a rare bacteria called Arcanobacterium haemolyticum. And in addition to the F. necrophorum, as well as discussing the complications of Streptococcal infections I emphasized my teaching around A. haemolyticum.

The following information was extracted from the 2009 AAP "Red Book".  A. haemolyticum is a catalase-negative, facultative anaerobic gram-positive bacillus formerly classified as Corynebacterium haemolyticum. Humans are the primary reservoir and spread is person to person, via droplet respiratory tract secretions and pharyngitis occurs primarily in adolescents and young adults. It is estimated that it causes 0.5% to 3% of all acute pharyngitis. The incubation period is unknown.
Clinically, it causes an acute pharyngitis indistinguishable from that caused by group A streptococci (GAS): fever, pharyngeal exudate, lymphadenopathy, rash, and pruritus are common; in almost half of all reported cases, a maculopapular or scarlatiniform exanthem is present, beginning on the extensor surfaces of the distal extremities, spreading centripetally to the chest and back, and sparing the face, palms, and soles. In comparison with GAS, palatal petechiae and strawberry tongue are absent.
Other clinical manifestations include URI and LRI that mimic diphtheria, including membranous pharyngitis, sinusitis, and pneumonia; and skin and soft tissue infections, including chronic ulceration, cellulitis, paronychia, and wound infection. Invasive infections, including septicemia, peritonsillar abscess, Lemierre syndrome, brain abscess, orbital cellulitis, meningitis, endocarditis, pyogenic arthritis, osteomyelitis, urinary tract infection, pneumonia, and pyothorax have been reported. No nonsuppurative sequelae have been reported.
The treatment of choice is erythromycin. A haemolyticum has in vitro susceptibility to erythromycin, clindamycin, and tetracycline. It is generally resistant to penicillin and trimethoprim-sulfamethoxazole, although penicillin resistance is variable. According to the Red Book, in disseminated infection, parenteral penicillin plus an aminoglycoside may be used initially as empiric treatment.


The residents were very surprised and expressed fascination with the newly acquired knowledge; the fourth year medical student was avidly writing down in her small notebook the name of the bacteria, as well as the references to read afterwards.

I felt well. The residents discovered a new world behind what they thought was a well known subject to them; we discussed the classic complement profile (C3 and C4) in post-streptococcal glomerulonephritis; we discussed about Rheumatic Fever and the Jones' criteria, about Streptococcal Toxic Shock Syndrome (STSS) and the controversial PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections) syndrome. They know more than they did before the rounds; this was teaching provided with only 2 cases of 15 we rounded. Of course a lot of other teaching points came out, but it was very satisfying to witness first-hand the progress of the Pediatric residents converting themselves in "Children's internists".

The other cases were fascinating as well, we had a baby with recurrent MRSA abscesses, which oriented the teaching toward the immune deficiencies that can predispose to recurrent staphylococcal abscesses; we had some epileptic patients using novel antiepileptic drugs such as lacosamide and rufinamide.

I strive, that regardless of how "common and boring" a disease may appear, it can be as fascinating as you want it to be, but this requires the imagination and creativity of the academic hospitalist to ask questions that stimulates his/her own thinking as well as the resident's and medical students. The knowledge can be unlimited, especially if you go to intricate pathophysiologic or biochemical aspects of the disease, or as well into pharmacology.

Pediatrics is fascinating; I can't never end being so grateful for the blessing I received in becoming a Pediatrician. Tomorrow is Sunday and we'll make it an efficient day; have the resident's leave early to comply with duty hours, but I do expect to provide some focused teaching.

As always, primum non nocere...