Long-term effects of glandular fever: what stays and what recovers

The long-term effects of glandular fever are limited for most people: complaints fade over months and nothing lasting is left behind. A minority stays affected longer. In a cohort of 301 adolescents, 13 percent still met chronic fatigue criteria at six months, 7 percent at one year and 4 percent at two years (PMID 19564299).

Those three figures are worth the whole article.

I put them up front deliberately, because online you mostly find the extremes. Either it passes by itself, or you read an account of years in bed. Reality is a falling curve, and that is something to hold on to.

What is the normal course after glandular fever?

The acute complaints clear in two to three weeks and the fatigue runs two to three months according to the Dutch public health institute RIVM. Reduced tolerance for effort is ordinary in that window, even when nothing else bothers you. The trend should be rising across those months.

A flat line is the signal, not a bad day.

A good week followed by a setback belongs to it. Three months without any improvement does not.

The researchers also saw that the group still affected at two years had already scored clearly higher on fatigue at twelve months than the rest. So the course in the first year says something about the second.

Can glandular fever flare up again later?

The Epstein-Barr virus stays in your body for life and can become active again, usually without you noticing. Going through full glandular fever a second time is unusual. What people experience as a return is more often a dip inside a recovery that was never finished.

That distinction is practically useful.

Imagine two men who both have a bad week 9 months after glandular fever. In one, fever and swollen glands come back. In the other it is only tiredness after a busy work week. Only the first has something new.

A new infection asks you to wait it out. An unfinished recovery asks for a different build-up. How to tell the two apart through the antibody pattern is in Epstein-Barr virus symptoms.

Is it down to your fitness?

Probably not. Huang and colleagues followed adolescents after glandular fever and checked whether their activity level before the infection predicted who developed prolonged fatigue. They did not find that link (PMID 20819961). Being fit does not protect you here the way you would hope.

For athletes that is an uncomfortable result.

The Dubbo study pointed the same way: what predicted the course was the severity of the acute illness, not someone's background or psychological profile (PMID 16950834). Those hit hardest carried the highest risk of a long tail.

I find that freeing. It takes the guilt away from people who think they trained back too early or are not trying hard enough.

Is anything left behind in your organs?

Usually not. In glandular fever the liver and spleen can swell temporarily and liver values can stay raised for a while. As a rule those return to normal on their own, though it may take weeks. Thuisarts describes the liver usually starting to work properly again by itself.

The spleen does deserve respect in that period.

That is exactly why a separate pause applies to contact and collision sport in the first weeks. Which timeline goes with it is in how long glandular fever lasts.

When should you have blood drawn?

When the fatigue is not measurably easing after roughly three months. Blood testing does not demonstrate a post-viral course, but it can reveal other explanations that fit persistent tiredness just as well. Iron deficiency, thyroid problems, a B12 shortfall and ongoing inflammatory activity head that list.

Ruling out what is treatable comes before attaching a label.

Values that often come into view are ferritin, TSH, vitamin B12 and hs-CRP. That group sits together in the 360 health panel, and the broader overview is in blood test for fatigue.

If there is a clear worsening that only arrives a day after effort, that deserves separate discussion. See post-exertional malaise.

My advice: note your longest session and your resting heart rate every week, and lay the series side by side after three months. A falling series is reassuring; a flat one you take to your GP.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

References

• Katz BZ, Shiraishi Y, Mears CJ, Binns HJ, Taylor R. Chronic fatigue syndrome after infectious mononucleosis in adolescents. Pediatrics, 2009;124(1):189-93. PMID 19564299.
• Huang Y, Katz BZ, Mears C, Kielhofner GW, Taylor R. Postinfectious fatigue in adolescents and physical activity. Archives of Pediatrics and Adolescent Medicine, 2010;164(9):803-9. PMID 20819961.
• Hickie I, Davenport T, Wakefield D, et al. Post-infective and chronic fatigue syndromes precipitated by viral and non-viral pathogens: prospective cohort study. BMJ, 2006;333(7568):575. PMID 16950834.
• RIVM. Glandular fever (ziekte van Pfeiffer), questions and answers.
• Thuisarts.nl. I have glandular fever (Ik heb de ziekte van Pfeiffer).