Month: December 2022

Why Does My Young Female Patient Have Recurrent Spontaneous Pneumothoraces?

FA Manian MD, MPH, , , , , , , , , , , , Leave a comment

Causes of spontaneous pneumothorax are legion, including cigarette use, genetic predisposition, or most commonly subpleural bleb rupture. 1 However, in cases without an apparent cause, a young female patient with recurrent spontaneous pneumothorax should routinely be asked about the timing of the pneumothorax in relation to her menstrual periods.  If related, catamenial pneumothorax (CP)— also known as menses-associated pneumothorax—should also be considered.  

CP is commonly defined as 2 or more episodes of spontaneous pneumothoraces occurring within 72 hours of onset of menstruation. 2, 3 Classically, CP occurs in females between the ages of 30-40 years with a history of endometriosis and recurrent right-sided pneumothorax.

As for potential mechanisms to explain catamenial pneumothorax, several theories have been proposed, including the passage of air through the vagina and uterus during times of decreased cervical mucus production and peritoneal cavity into the pleural space via diaphragmatic fenestrations. 3 Another potential mechanism is the retrograde migration of endometrial tissue from the uterine lining via the right paracolic gutter into the pleural space through defects in the diaphragm. Endometrial necrosis following monthly cycles may then create air blebs and pneumothorax. 3,4 Although CP is the most common presentation of thoracic endometriosis, a diagnosis of endometriosis is not required for its diagnosis.3, 5

Initial evaluation of CP often includes chest X-ray, CT, or MRI which may show not only pneumothorax but also diaphragmatic nodules or fenestrations; CA-125 levels may also be elevated in CP due to endometriosis. 2,3,9  Endometriosis-related CP is diagnosed via video-assisted thoracoscopic surgery (VATS).  

Treatment includes surgical and medical options but, ultimately, the goal is to prevent recurrence which is more likely in CP compared to other pneumothoraces. 3, 6 Surgical approaches such as VATS, pleurodesis, and diaphragmatic plication or repair with mesh, may be considered but recurrence rates (8-40%) are common. 3,7 Treatment options also include hormone-suppression therapy resulting in atrophy of ectopic endometrial glands (eg, estrogen-progesterone oral contraceptives and gonadotropin-releasing-hormone [GNRH] agonists such as leuprolide). 2, 7

Bonus Pearl: Did you know that a condition called catamenial epilepsy also clusters around menstruation due to the diminished protective effect of progesterone against seizures?  10

Contributed by Mariam Krikorian, Medical Student (Lincoln Memorial University) Mercy Hospital-St. Louis

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References

  1. Sahn, Steven A., Heffer, John E. Spontaneous Pneumothorax. N Engl J Med. 2000;342:858-874. https://www-nejm-org.lmunet.idm.oclc.org/doi/10.1056/NEJM200003233421207?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed.
  2. Haga, T., Kumasaka, T., Kurihara, M, etal. Immunohistochemical Analysis of Thoracic Endometriosis. Path Intl, 2013;63(9);429-434. https://onlinelibrary.wiley.com/doi/10.1111/pin.12089.
  3. Visouli, A. N., Zarogoulidis, K., Kougioumtzi, I., etal. Catamenial Pneumothorax. J Thora Dis. 2014;6(4). https://jtd.amegroups.com/article/view/3205/html.
  4. Rousset-Jablonski, C., Alifano, M., Plu-Bureau, G., etal. A. Catamenial Pneumothorax and Endometriosis-Related Pneumothorax: Clinical Features and Risk Factors. Mol Hum Reprod. 2011;26(99);2322-2329. https://academic.oup.com/humrep/article/26/9/2322/720483.
  5. Korom, S., Canyurt, H., Missbach, A., etal. Catamenial Pneumothorax Revisited: Clinical Approach and Systematic Review of the Literature. J Thorac Cardiovasc Surgery. 2004;128(4);502-508. https://www.jtcvs.org/article/S0022-5223(04)00772-X/fulltext.
  6. Haga, T., Kurihara, M., Kataoka, H., etal. Clinical-Pathological Findings of Catamenial Pneumothorax: Comparison Between Recurrent Cases and Non-Recurrent Cases. Ann Thorac. 2014;202(6);202-206. https://www.jstage.jst.go.jp/article/atcs/20/3/20_oa.12.02227/_article.
  7. Leong, A. C., Coonar, A. S., Lang-Lazdunski, L. L. Catamenial Pneumothorax: Surgical Repair of the Diaphragm and Hormone Treatment. Ann R Coll Surg Engl. 2006;88(6). https://publishing.rcseng.ac.uk/doi/10.1308/003588406X130732.
  8. Marjański, T., Sowa, K., Czapla, A., etal. Catamenial Pneumothorax – A Review of the Literature. Polish Journal of Thoracic and Cardiovascular Surgery. 2016;13(2);117-121. https://www.termedia.pl/Catamenial-pneumothorax-a-review-of-the-literature,40,27920,0,1.html.
  9. Bagan, P., Le Pimpec Barthes, F., Assouad, J, etal. Catamenial Pneumothorax: Retrospective Study of Surgical Treatment. Ann Thorac. 2022;75(22);378-381. https://www.annalsthoracicsurgery.org/article/S0003-4975(02)04320-5/fulltext.
  10. Herzog, Andrew. Catamenial Epilepsy: Definition, Prevalence, Pathophysiology and Treatment. Elsevier Sci. 2008;17;151-159. https://pubmed-ncbi-nlm-nih-gov.lmunet.idm.oclc.org/18164632/.

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Why Does My Young Female Patient Have Recurrent Spontaneous Pneumothoraces?

Is loss of sense of smell or taste much less common in Omicron-related Covid-19 compared to earlier strains of SARS-CoV-2?

FA Manian MD, MPH, , , , , , , , , , , , Leave a comment

Absolutely! Although loss of smell was a cardinal symptom of Covid-19 with earlier strains of SARS-CoV-2 (eg, Wuhan, alpha, delta), on average omicron causes olfactory dysfunction in only 13% of patients, 3-4 times lower than the earlier strains.1

But why is omicron less likely to causes loss of smell or taste? There may be at least 2 explanations. First explanation revolves around the solubility of omicron in the olfactory mucus. Recall that to access the olfactory epithelium, viruses and other pathogens have to first dissolve in and penetrate the mucus layer that not only allows odorants to reach the olfactory receptors but also protects the olfactory epithelium from toxins and pathogens. Hydrophilic and acid proteins can penetrate the mucus barrier more easily because they are more soluble in the mucus layer.1

What does this have to do with omicron? Well, it turns out that omicron with all its mutations in the spike protein is actually more alkaline than the Wuhan and delta strains. This means that omicron may have lower solubility in mucus and have a harder time reaching and infecting the olfactory epithelium. 1 Since the composition of olfactory mucous differs significantly from other mucus layers in the respiratory tract, omicron may still cause disease.2

Another potential mechanism may be related to the inefficiency of omicron in other steps necessary to infect nonneuronal cells of the olfactory epithelium within the nasal cavity, such as the endosomal route. 1 It turns out that cells of the olfactory epithelium express less of the endosomal membrane fusion proteases (cathepsins) which omicron prefers for cell entry! Fascinating! 

Bonus Pearl: Did you know that only 5-10% of functional olfactory neurons are required for a relatively normal sense of smell? This means that SARS-CoV-2 needs to eliminate at least 90% of all support cells of the olfactory neurons within a 3-4 day period (before their regeneration) for the host to notice anosmia?

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References

  1. Butowt R, Bilinska K, von Bartheld C. Why does the omicron variant largely spare olfactory function? Implications for the pathogenesis of anosmia in coronavirus disease 2019. J Infect Dis 2022;226:1304-1308. Why Does the Omicron Variant Largely Spare Olfactory Function? Implications for the Pathogenesis of Anosmia in Coronavirus Disease 2019 – PubMed (nih.gov)
  2. Yoshikawa K, Wang H, Jaen C, et al. The human olfactory cleft mucus proteome and its age-related changes. Sci Rep 2018;8:17170. The human olfactory cleft mucus proteome and its age-related changes – PMC (nih.gov)
  3. Harding JW, Getchell TV, Margolis FL. Degeneration of the primary olfactory pathway in mice. V. Long-term effect of intranasal ZNS04 irrigation on behavior, biochemistry and morphology. Brain Res 1978;140:271-85. Denervation of the primary olfactory pathway in mice. V. Long-term effect of intranasal ZnSO4 irrigation on behavior, biochemistry and morphology – PubMed (nih.gov)

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Is loss of sense of smell or taste much less common in Omicron-related Covid-19 compared to earlier strains of SARS-CoV-2?