Information about the handbook

Despite the growing recognition of Post-Acute Infection Syndromes (PAIS), including Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long COVID, significant challenges remain in their objective diagnosis and effective therapeutic management. Current diagnostic criteria often rely on subjective patient reports, leading to diagnostic delays and variability, while the underlying pathophysiology, particularly mitochondrial dysfunction, remains incompletely understood and difficult to quantify objectively in a clinical setting. Furthermore, a clear clinical model that integrates diverse findings and guides targeted interventions is lacking.

This e-book provides a comprehensive guide dedicated to the diagnosis and therapy of PAIS, ME/CFS, and Long COVID. It addresses the clinical questions raised by these syndromes in the uncharted territory between illness and health.

The handbook combines decades of clinical experience and recent research insights to provide healthcare professionals and patients with a structured framework for understanding, diagnosing, and treating these conditions. Objective assessment methods, such as the hand dynamometer test, and knowledge about interactions of the immune system, metabolic dysfunction, and therapeutic approaches, including mast cell stabilization and treatment with low-dose naltrexone, are presented.

The handbook begins with an introduction that outlines the purpose and scope, emphasizing the need for objective diagnostic tools and effective treatments for ME/CFS and Long COVID. It also highlights the dynamic nature of our knowledge and invites contributions and updates.

The evolution of diagnostic criteria is then discussed, covering the historical development and refinement of definitions from early criteria, such as Holmes and Fukuda, to the current guidelines from NICE and WHO. The emergence of core symptoms, such as post-exertional malaise (PEM), is explained, as are the challenges in standardizing Long COVID definitions.

Next, the nomenclature and conceptual framework are explored, addressing the history of the naming of ME/CFS and related syndromes, including terms such as Systemic Exertion Intolerance Disease (SEID) and Post-Acute Infection Syndrome (PAIS), with an emphasis on the biological basis and the patient’s perspective.

This is followed by an epidemiological overview with prevalence data from various regions, focusing on demographic patterns, geographical variations, and the substantial impact on public health.

The pathophysiology of these conditions is then discussed, with a focus on cellular bioenergetics, mitochondrial dysfunction, and metabolic blockages, such as the inhibition of pyruvate dehydrogenase. The role of mast cells and microglia in neuro-immune activation and the development of symptoms is also explained.

Following a detailed discussion of the pathophysiology, particularly cellular bioenergetics and mitochondrial dysfunction, the book introduces the hand dynamometer test as a reliable, non-invasive method for objectively measuring bioenergetic dysfunction in patients, including the test protocol, its reproducibility, and its role in clinical assessment and research. Building on this, the development of a clinical model for ME/CFS and Long COVID is presented, integrating clinical and laboratory findings into a unifying model that clarifies the interrelationships between symptoms, survival strategies, immune activation, metabolic dysfunction, and oxidative stress in PAIS.

A specialized chapter further extends this insight to pediatric post-acute infection syndromes, addressing the diagnosis, epidemiology, and treatment of pediatric ME/CFS and Long COVID, with an emphasis on early recognition, autonomic dysfunction, and tailored educational adjustments.

A separate chapter defines the subgroup of patients with very severe PAIS, describing clinical characteristics, functional limitations, and pathophysiology, including mitochondrial dysfunction and oxidative stress, and emphasizes the urgent need for specialized care. The practical care and treatment of these extremely vulnerable patients are described, including nursing care, nutritional support, and medical treatment.

Personal stories from patients illustrate the lived experience, diagnostic challenges, and societal neglect of ME/CFS and Long COVID, underscoring the importance of the patient perspective. Modesty and respect are also appropriate when dealing with a patient whose symptoms are not yet understood.

Problems with the stomach and intestines are often reported and less often noticed. It is a potentially life-threatening complication in severely and very severely ill patients.

The therapeutic potential of low-dose naltrexone (LDN) is discussed, including its pharmacodynamics, mechanisms of action, and preliminary clinical studies that support LDN as a possible treatment, in addition to other agents such as minocycline, cromolyn, mast cell stabilizers, and supplements targeting metabolic and immune-related disorders.

The manual also discusses medical specialties and challenges within the healthcare system, addressing the problems in classifying PAIS within existing specialties, barriers to recognition and funding, and the need to strengthen primary care and systemic support.

Finally, a step-by-step, individualized therapeutic strategy is described, aimed at optimizing circulation, stabilizing the immune system, treating metabolic blockages, improving fatty acid oxidation, and reducing oxidative stress, with an emphasis on patient-centered care and symptom management.

This guide serves as an evolving clinical guideline intended to bridge knowledge gaps and improve outcomes for patients with ME/CFS, Long COVID, and related syndromes. The book acknowledges that it does not answer all questions and contains no absolute truths but hopes to contribute to the essential connection between basic science and clinical practice.

The manual is never complete; the version currently available online still requires much improvement and expansion. Therefore, we offer a subscription to continuously changing content that we create for you together with colleagues.