Figure 3. Gram-positive cocci in chains. Source: James H. Brien, DO.
Figure 4. Streptococcus pneumoniae. Source: James H. Brien, DO.
Answer and discussion:
The culture of draining material from this patient’s right eardrum grew S.. pyogenes (Group A streptococci), which is the second most likely “real” pathogen of acute mastoiditis. Pseudomonas aeruginosa has been occasionally implicated, but most commonly the bacteria in this age group represent a sampling failure due to surface contamination from the ear canal. S.. lung infection by far tops the list of causes of acute mastoiditis if the right culture technique is used S.. pyogenes be a distant second. In the age of enhanced, conjugated pneumococcal immunization, however, the chances of pneumococci causing acute mastoiditis are significantly lower than previous studies suggested. In the case presented here, the clue is in the Gram staining.
From time to time we should go back to review some basic “school medical microbiology”. A properly performed Gram stain of S.. pyogenes would show some chains of gram-positive (blue colored) cocci, as shown in Figure 3, while those of S.. lung infection would most likely be lancet-shaped, gram-positive diplococci (Figure 4). In terms of H. flu Type b (Hib) would show the Gram stain of gram-negative (red colored) pleomorphic rods, as shown in Figure 5. Pleomorphism means variable size and / or color. In a fully immunized patient, Hib is very rare, which also speaks against this choice. S.. aureus falls in the ranking of similarities in third or fourth place. Classic, S.. aureus appears as a cluster of gram-positive cocci, as shown in Figure 6. The trap in the interpretation of the Gram stain can lie in the staining technique or the âfake-outâ of the size and shape of the organism. For example, gram-negative diplococci may actually be gram-negative rods with bipolar staining. I messed with it during my fellowship, much to the amusement of my program director James W. Bass, MD. So how did it look Meningococci in my naive eyes at the microscope it turned out to be Hib. You may also notice that all of these organisms are italicized or underlined by common convention, and that the word grief is capitalized except when it relates to the staining results and reflects the name of the inventor of the stain. Hans Christian Gram, 1884. End of the microbiology refresher course.
The swelling of the soft tissue over the mastoid or post-auricular area causes the auricle to shift forward, as seen in Figure 1. However, not all protruding auricles are caused by acute mastoiditis. There are other causes of this swelling, such as: B. an insect bite on the auricle, a collection of herpes lesions (more common than you think), or some other form of injury to the auricle or post-auricular area.
Acute mastoiditis is virtually always a complication of AOM in a patient with a history of recurrent AOM. There are exceptions, however. The usual treatment approach includes antimicrobial therapy aimed at the usual causes, upcoming culture results and surgical placement of PE probes, if not already present, with surgical drainage and, if necessary, debridement of the mastoid process. Generally recommended antimicrobial agents include a broad spectrum beta-lactam, such as a third generation cephalosporin plus clindamycin, pending culture results. Adolescent patients may use an anti-pseudomonal beta-lactam due to the increased likelihood of real P.. aeruginosa Infection. Complications with proper treatment are rare. One such complication is facial palsy, which is usually present at the presentation site. Another possible complication is bacterial meningitis, which should be ruled out by testing or safe clinical criteria. The patient in this case with the growth of S.. pyogenes, finished his treatment with penicillin G and clindamycin (7 days in the hospital) with good clinical results and switched to high-dose oral amoxicillin for an additional 3 to 4 weeks.
Figure 5. Haemophilus influenzae. Source: James H. Brien, DO.
Figure 6. Staphylococcus aureus. Source: James H. Brien, DO.
I would guess with confidence that we all had someone who had a strong influence on our choice of specialty (and subspecialty), usually as a 3rd approx – or 4 NS -year-old student. My mentor on pediatric infectious diseases who also happened to be a brilliant general pediatrician and hospital physician before such a name was used was Warren A. Todd, MD, who died on July 20th at the age of 81 after a private battle with a long illness. Warren was At the P. pediatric I contagious D. iseases staff at Fitzsimons Army Medical Center in the 1970s, where we met in the summer of 1975 when I was on a 3rd there was approx -year change of students. He was a passionate and compassionate teacher with a broad medical knowledge that I have not come across from any other colleague, and he inspired me to pursue a similar career; a worthy goal that I could never achieve. The bar was just too high, but I could try better. Like many of you, I called my teachers early in my postgraduate years with difficult questions for reassurance . I would ask Warren for help with any ID question I had before my Community. Later in my career, I called him to get his thoughts on leadership, politics, or life in general, not only because of his common sense, but he also retired from the army B. rigadier G General, with the command experience associated with this rank. He was like having a brilliant older brother who really enjoyed it hearing from you, problems and everything. During my residency he took me to the “C.ouchB.ell âon rounds that he rang when he sensed the presence ofâ bull droppings âfrom the mouth of the presenting student or resident – an effective teaching practice that I took with me.
He didn’t bother people with his own problems. I spoke to him exactly 2 weeks before he died and I still didn’t know he was sick. That is the character of greatness. Farewell woo Courting , from your favorite resident, Jim Bob.
For more informations:
Brien is a member of the Infectious diseases in children and Infectious Disease News Editorial Boards and Associate Professor of Pediatric Infectious Diseases at McLane Children’s Hospital, Baylor Scott & White Health, in Temple, Texas. He can be reached at [email protected]