Defining Pediatric CFIDS

By Karen Lang

Originally published in The CFIDS Chronicle, Winter 1997

Karen Jordan, PhD is project director of the chronic fatigue syndrome (CFS) epidemiology study at DePaul University in Chicago. She moderated a panel at the October 1996 American Association for Chronic Fatigue Syndrome’s research conference that addressed the question, "Do we need a CFS case definition for children under 10?" All of the panelists agreed that a specific set of criteria needs to be developed for pediatric CFS, but they differed in their individual approaches to the question.

David S. Bell, MD
Dr. Bell argued for specific pediatric case definitions for research and for clinical evaluation and diagnosis of CFS in children. He said there are two factors that need to be identified and separated in illness — the physiological basis of illness, and the patient’s behavioral adaptation to that physiological expression. He illustrated his point by saying that the outcome of juvenile diabetes mellitus is influenced by the child’s decision whether or not to take insulin.

Not having a definition for CFS can be disastrous for the child with the disease, he said. Lacking a definition and description of the physiological aspects of the illness, it is easy to assume that the child’s problem is psychological.

Confusion results when the child is given the message that there is no physiological abnormality, and that his or her problem is the result of "some weakness in character." If the child is unable to sort out whether he or she is really sick or is crazy like everyone says, it can cause a crisis in identity formation that can have lifelong implications. A specific CFS case definition for children, including a description of the illness and of how to make the diagnosis, would establish the physiological expression of the illness as well as the behavioral aspects, making it easier for young people with CFS to grow up with healthy self-identities.

James Jones, MD
Dr. Jones said he agreed with Dr. Bell that a specific definition is necessary if the diagnosis of CFS can be made in children. One of the problems in trying to define CFS in children (people 12 years of age and younger) is that a child’s illness is usually reported or described by the child’s parents or other caregivers, rather than by the child him or herself. The physician has to rely on second-hand information.

The role of the caregivers in the description of childhood illness needs to be carefully studied, Dr. Jones said. He gave an example of a mother with CFS who thought her daughter also had CFS. A thorough medical evaluation revealed that the daughter had Crohn’s disease, not CFS. It was a case, he said, of the mother trying to explain the daughter’s illness on the basis of her own symptoms. He asked, "Who is going to benefit by assigning CFS to younger children — the kids or the doctors who take care of them?"

He cautioned attendees about "vulnerable child syndrome," a situation wherein a child with a family illness history learns that response to illness is a way of life. He concluded by saying that there is much to be learned about CFS in younger children.

Leonard A. Jason, PhD
Dr. Jason, the principal investigator for the federally funded CFS epidemiology study at DePaul University, said that a great deal of study will be required to determine if CFS exists in children under 10 years of age. In order to create a valid definition, scientists need clear, objective signs and clear ways of gathering information. A good definition is necessary, as is a good way of assessing the definition. Test–retest reliability must be established, he said.

Dr. Jason shared data from the epidemiology studies conducted by DePaul University researchers. The first study involved random telephone calls to 1,000 people in Chicago asking if anyone in the household had experienced fatigue lasting for six months or longer. Following detailed examinations of those who reported CFS symptoms, two cases of CFS were found. This translates to 200 cases per 100,000 adults, which is comparable with current CDC estimates of 76–233 CFS cases per 100,000.

The second study, which is currently underway, involves random phone calls to 26,000 people in the Chicago area. So far, three to four percent of the sample meets all of the criteria for the 1994 CDC definition based on self-report of symptoms. Medical evaluations to rule out other explanations for illness will follow.

Dr. Jason suggested the following modifications to the 1994 case definition for use in children:

• Remove "persistent or relapsing fatigue… that has not been life-long." This symptom may have been life-long in children.
• Remove "fatigue is… not the result of ongoing exertion." On a bad day, exertion in and of itself can cause fatigue.
• Change "not substantially alleviated by rest." Some CFS patients report that if they operate within the "envelope" of the limitations imposed by the illness, they function fairly well.
• Change "post-exertional malaise lasting more than 24 hours" because it is an arbitrary figure.
• Remove the exclusion for anorexia nervosa and bulimia if the conditions have been resolved.
• Remove the exclusion for melancholic depression.

Karen Jordan, PhD
Dr. Jordan proposed a starting point for a pediatric case definition. Citing problems in applying the 1994 CDC definition to children, she suggested additional modifications to those offered by Dr. Jason:

• Remove "occupational" from "reduced activities."
• Use "frequent headaches" instead of "headaches of a new type, pattern or severity."
• Add symptoms that are characteristic of CFS in children — abdominal pain; rash; fever, chills or night sweats; eye pain or light sensitivity; dizziness or lightheadedness — but keep the required symptom minimum at four.
• Exclude childhood diseases such as cystic fibrosis and muscular dystrophy.
• Do not exclude fibromyalgia, multiple chemical sensitivities or school phobia.

• A standardized definition offers a method of comparability between research studies, even if it is imperfect to begin with. It can be built upon and adapted as necessary, she said.
• Naming and describing the illness is beneficial for the patient. Not knowing what is going on leads to self-doubt and fear.
• A definition will help physicians and parents help the child set realistic expectations for his/her activity levels and limitations.

• A pediatric CFS definition might become a "wastebasket," an easy diagnosis that satisfies patients and fails to recognize the presence of other treatable illnesses.
• There is still confusion about the true disease process in children.
• The stigma of chronic illness may be hard for children to bear.

Dr. Jordan finished by offering the following observations for future directions in research:

• The word "fatigue" is not used much by parents to describe this symptom in their children.
• A thorough medical examination is necessary to confirm the diagnosis of CFS.
• Longitudinal studies are important to see what is happening to these children down the road.

Other Observations
The following comments and observations were made by members of the audience and panel during the question and answer period:

• "Fatigue" is hard to define in adults, let alone in children. It may mean sleepiness, malaise or muscle weakness. Perhaps fatigue is a change in normal activity for kids, with less play, more sleep and problems in school. Parents might not notice a symptom like "fatigue" as much as they might notice that the child is not doing what they are expected.
• Dr. Bell said that of the 230 CFS patients he treated in Lyndonville, 60 of whom were children, after 10 years not a single patient has been subsequently diagnosed with another illness.
• There is concern about giving an open-ended diagnosis of CFS to a child, lest the child "learn" to have CFS over the years.
• Dr. Bell suggested subgrouping young children who appear to be fatigued, children with a history of excessive ear/sinus infections who eventually progress to a state resembling CFS, and children who have illness as preschoolers, appear to recover, but develop a CFS-like illness years later.
• It is the clinician’s job to rule out other illnesses, and therefore it may not be necessary to list every possible exclusion in the definition.
• The definition for children should be "operational": doctors and parents should describe children according to functional state rather than labeling them with CFS, which may not be in the child’s best interest.