In the meantime, a first guideline (S1 Leitline Post-COVID / Long-Covid) [Koczulla] has been published by a consortium of German medical societies under the leadership of the German Society for Pneumology. Describing the syndrome in detail, the paper includes therapeutic and diagnostic options.

Various psychosomatic and psychosocial conditions can exacerbate the disease. The causes have not been clarified, but the persistence of viruses or of virus components for weeks and months is likely, as confirmed by tissue samples. Further possible pathomechanisms are discussed: Post-infectious structural tissue damage, including endothelial damage and impaired micro-vascularization, hypercoagulability and thrombosis, as well as chronic immune dysregulation.

In conclusion, the following key statements are summarized:

    • Complex clinical findings as found in post/long COVID require a wholistic, interdisciplinary approach, as well as a continuity in care, postulating an increasing specialization in the health care system.
    • After a SARS-CoV-2 infection, (newly occurring) symptoms or complaints raise the suspicion of a post/long COVID syndrome. Yet other differential diagnoses must be considered and, if necessary, ruled out.
    • The diagnosis of a post/long COVID syndrome cannot be objectified by a single examination or by a set of laboratory data. Likewise, normal laboratory values ​​do not rule out a post/long COVID syndrome.
    • A further specialist medical clarification may be indicated if conditions persist for more than 3 months after a SARS-CoV-2 infection.
    • Patients with severe lung involvement can (almost) completely recover. If symptoms persist, e.g. for longer than 3 months, a pneumological consultation is required.
    • The effectiveness of a therapeutic vaccination in patients with post-COVID is uncertain. A vaccination should only be considered in the frame of studies.

    The pathogenesis of long-Covid is assumed to vary individually, within a broad range. Detectable in the tissue over several months, the persistence of viruses or of their components may play a decisive role and, above all, proliferate persistent inflammation.

    A specific therapy is not yet known. A vaccination was able to bring about a statistically significant improvement of the symptoms compared to a comparison group, although the differences were not substantial, and at the same time there was also a worsening in a large number of the patients.

    A thorough anamnestic status assessment is necessary prior to care. "A poor general condition, significant weight loss, inexplicable or newly occurring neurological deficits or abnormalities, new pain symptoms, bad or worsening somatic or psychological findings as well as inexplicable abnormalities in the basic diagnosis" ... "should give rise to an in-depth diagnosis and/or a referral, e.g. to a post-COVID outpatient clinic ”, as stated in the S1 Guideline. A simple scale should be used with classification into "no or negligible" functional restrictions (no significant limitations in everyday life and at work) or "slight", "moderate" or "severe" functional restrictions, which usually lead to longer complaints.

    In the case of chronic hyperinflammation and autoimmunity, no functional diagnostics are recommended in addition to the usual laboratory testing for the detection of lymphopenia (reduced lymphocyte count, probably due to T-cell deficiency). Endothelitis is also not mentioned in this context, although the hyperinflammation is usually expressed in an endothelial dysfunction.