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Feature Christmas 2017: All Creatures Great and Small

The science behind “man flu”

BMJ 2017; 359 doi: (Published 11 December 2017) Cite this as: BMJ 2017;359:j5560

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Re: The science behind “man flu”: explanations by health communication rather than symptoms and suffering

One cannot but agree with the interesting and timely mini review on “man flu”.(1) However, we believe that this notion might be better explained in terms of health communication, rather than immune functioning or suffering from a cold. Thus, man flu is more likely to concern whether men more often exaggerate their symptoms or communicate it differently from women.

In a study of 1700 people with the common cold, Sue MacIntyre found that men slightly more often over-rated their symptoms (20% vs. 14% in women) compared with the judgement by a clinical observer.(2) The cross sectional nature of the study did, however, not allow the author to conclude whether this was due to men being less tolerant of sickness symptoms, more likely to complain about them, or whether the clinician were more likely to under-estimate symptoms in men. In addition, there is a mixed bag regarding sex differences in suffering, some supporting men to suffer more (e.g. when being affected by multiple illnesses),(3) and others supporting women to complain more as well as developing an impaired pain regulation during infections.(2 4) However, the majority seem to find few or no differences in symptom ratings between men and women during acute infections.(5 6)

It is not surprising that Sue highlighted a need for more high-quality studies, with experimental protocols.(1) In fact, we recently injected healthy men and women with a bacterial endotoxin, causing systemic inflammation and a sickness response similar to the flu.(7) Men and women moaned and complained equally, but the frequency of sighs/deep breaths was increased amongst sick men but not in women. While the increase of sighing and deep breaths when sick may relate to relief,(8) they are also likely to serve communicative functions.(9) While fulfilling the experimental control criteria wanted by Sue, a weakness of the Lasselin 2018 study is that only communication towards female caretakers was examined. Nonetheless, this study supports that men and women differ very little when rating their sickness symptoms, but adds that they communicate their symptoms differently.

Health communication is highly dynamic, and patients do not only express their suffering verbally, but also engage in a number of sickness related behaviours. The ability to detect non-verbal sickness symptoms in other humans is a growing research field, where e.g. facial features, gait patterns and smell can be used by laymen to detect acute sickness.(10-12) Reasonably, these abilities are fine-tuned during clinical practice, and hopefully not differentially applied across genders to under-rate symptoms in men, as suggested by.(2) If this finding would be replicated, society runs the risk of having men claiming that they need to exaggerate symptoms for compensatory reasons.

Also noted in the review is the need to further study how friends and family interpret sickness signs in their close ones. This is a highly interesting research area since some groups are more sensitive to the exposure of sick people. For example, people with health anxiety become more worried, anxious, and disgusted when exposed to photos of sick people.(13)

In all, recent evidence suggests that the “man flu” concept should be further scrutinized in terms of sex differences in non-verbal communication. At present, it is the omnipresence of the conception, rather than the empirical support for the behaviour, that speaks for the validity of “man flu”. Regardless, studies on the dynamics of communication between patients, their partners, families and caregivers are not only likely to give important cues for the existence of this notion, but more importantly, provide us with knowledge of how to improve detection and diagnosis of infections.

1. Sue K. The science behind "man flu". Bmj 2017;359:j5560. doi: 10.1136/bmj.j5560
2. Macintyre S. Gender differences in the perceptions of common cold symptoms. Soc Sci Med 1993;36(1):15-20.
3. Kesavayuth D, Rosenman RE, Zikos V. Personality and health satisfaction. Journal of Behavioral and Experimental Economics 2015;54:64-73.
4. Karshikoff B, Lekander M, Soop A, et al. Modality and sex differences in pain sensitivity during human endotoxemia. Brain Behav Immun 2014 doi: 10.1016/j.bbi.2014.11.014
5. Engler H, Benson S, Wegner A, et al. Men and women differ in inflammatory and neuroendocrine responses to endotoxin but not in the severity of sickness symptoms. Brain Behav Immun 2016;52:18-26. doi: 10.1016/j.bbi.2015.08.013
6. van Eijk LT, Pickkers P. Re: The science behind “man flu”: less inflammation, but more suffering in men than women. Bmj. 14 December 2017 ed, 2017.
7. Lasselin J, Lekander M, Paues-Goranson S, et al. Communication of health in experimentally sick men and women: A pilot study. Psychoneuroendocrinology 2018;87:188-95. doi: 10.1016/j.psyneuen.2017.10.024
8. Vlemincx E, Meulders M, Abelson JL. Sigh rate during emotional transitions: More evidence for a sigh of relief. Biol Psychol 2017;125:163-72. doi: 10.1016/j.biopsycho.2017.03.005
9. Teigen KH. Is a sigh "just a sigh"? Sighs as emotional signals and responses to a difficult task. Scand J Psychol 2008;49(1):49-57. doi: 10.1111/j.1467-9450.2007.00599.x
10. Olsson MJ, Lundstrom JN, Kimball BA, et al. The scent of disease: human body odor contains an early chemosensory cue of sickness. Psychol Sci 2014;25(3):817-23. doi: 10.1177/0956797613515681
11. Sundelin T, Karshikoff B, Axelsson E, et al. Sick man walking: Perception of health status from body motion. Brain Behav Immun 2015;48:53-6. doi: 10.1016/j.bbi.2015.03.007
12. Axelsson J, Sundelin T, Olsson M, et al. Identification of acutely sick people and facial cues of sickness. Proceedings B 2017 (in press) doi: 10.1098/rspb.2017.2430
13. Hedman E, Lekander M, Karshikoff B, et al. Health anxiety in a disease-avoidance framework: Investigation of anxiety, disgust and disease perception in response to sickness cues. J Abnorm Psychol 2016;125(7):868-78. doi: 10.1037/abn0000195

Competing interests: No competing interests

18 December 2017
John Axelsson
Julie Lasselin, Mats Lekander
Stress Research Institute, Stockholm University
114 19 Stockholm, Sweden