Juvenile primary fibromyalgia syndrome. A clinical study of thirty-three patients and matched normal controls

138
JUVENILE PRIMARY FIBROMYALGIA SYNDROME
A Clinical Study of Thirty-Three Patients and Matched Normal Controls
MUHAMMAD B. YUNUS and ALFONSE T. MAS1
Primary fibromyalgia syndrome (PFS) is a common and characteristic rheumatologic condition manifested by diffuse musculoskeletal aches, pains, and
stiffness frequently modulated by various factors, e.g.,
weather, physical activity, sleep quality, and anxiety/
stress, and accompanied by discrete tender points at
typical soft tissue sites. Although well-recognized in
adults, this entity has not been reported separately in
juveniles. This study documents PFS in 33 juveniles who
presented at age 17 or younger and compares their
findings with those in age- and sex-matched normal
control subjects. As in adult PFS patients, associated
non-musculoskeletal symptoms were common, including
fatigue, poor sleep, anxietyhtress, headaches, and paresthesias. Physical examination revealed multiple tender
points at characteristic soft tissue sites and no objective
evidence of arthritis. Routine laboratory test results
were normal or negative. Juvenile PFS is often misdiagnosed. Recognition of this common rheumatologic condition in juveniles is important in order to avoid unwarranted investigations and improper management.
Fibromyalgia syndrome, a form of nonarticular
____-
From the Department of Medicine, Division of Rheumatology, University of Illinois College of Medicine at Peoria, Peoria,
Illinois.
Supported in part by National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases grant AM-25663.
Muhammad B. Yunus, MD: Assistant Professor of Medicine; Alfonse T. Masi, MD, DrPH: Professor and Head, Department
of Medicine.
Address reprint requests to Muhammad B. Yunus, MD,
Department of Medicine, University of Illinois College of Medicine
at Peoria, P.O. Box 1649, Peoria, IL 61656.
Submitted for publication April 27, 1984; accepted in revised form September 24, 1984.
Arthritis and Rheumatism, Vol. 28, No. 2 (February 1985)
rheumatism manifested by diffuse musculoskeletal
aching and tender points at multiple characteristic
sites, is now established as a recognizable clinical
entity in adults (1-4). We prefer the term primary
fibromyalgia syndrome (PFS) rather than “fibrositis”
to underscore the absence of an underlying condition
(e.g., rheumatoid arthritis, osteoarthritis, trauma, or
hypothyroidism) which may also be associated with
similar clinical features. This term also indicates lack
of inflammation on muscle biopsy (5,6), as well as
presence of non-musculoskeletal features (3,7). Although PFS is now well described in adults, this
syndrome is not generally recognized among juveniles
and has not been separately described in this age
group. This report presents detailed results of a clinical study of PFS in 33 juveniles and matched normal
controls.
PATIENTS AND METHODS
Thirty-one patients were white and 2 were black, and
all but 2 were females. They had an age range of 9-17 years
at presentation (mean 14.7; median 15). The age of the
normal controls ranged from 9-19 years (mean 14.5; median
15). Onset age of PFS ranged from 5-17 years (mean 12.3;
median 13.5). The presentation and onset ages of patients by
subgroups are shown in Table 1. The most frequent age
group for both presentation and onset was 13-15 years. All
but 1 patient had onset before age 16, and 29 (88%) of the 33
patients presented between ages 13 and 17. The presentation
and onset ages of the 2 male patients were 15 and 14, and 14
and 10, respectively.
The mean (% 1 SD) height of patients was 157 ? 11.2
cm and of controls 154.7 ? 9.8 cm, with no significant
difference. The mean weight of patients was 45.7 12.1 kg
and of controls 39.6 % 7.0 kg ( P < 0.06). The mean observed
subjectlstandard height and weight ratios, according to age
*
JUVENILE PFS
139
Table 1. Distribution of presentation and onset ages in 33 juvenile
primary fibromyalgia syndrome patients
~~~~~~
Age group (vears)
Presentation
Onset
5-6
1-9
10-12
13-15
16-17
0 (0%)
3 (9%)
1(3%)
16 (49%)
13 (39%)
4 (12%)
5 (15%)
4 (12%)
19 (58%)
I(3%)
Total 5-17
33 (100%)
33 (1009%)
(S), were also calculated for patients and controls, with no
significant difference.
All 33 patients were age 17 or younger at presentation, and were seen consecutively by us in ambulatory
rheumatology consultation. Older patients with juvenileonset symptoms were not included. The age limit of 17 at
presentation was chosen instead of the suggested pediatric
age limit of 20 (9), or onset before age 16 as is the case for
juvenile rheumatoid arthritis (lo), because many pediatric
services include patients until age 17 (which is also the
maximum legal age for juveniles). The juvenile presentation
age is more reliable than onset age for consistency among
centers and for correct diagnosis of juvenile primary fibromyalgia, since time of symptom onset of this condition may
not be accurately recalled later in adult years and other
conditions at onset, e.g., viral arthralgia or arthritis, cannot
be ruled out by recall of symptoms alone.
Data were collected longitudinally by one of us
(MBY) according to a standardized protocol which included
a physician-administered questionnaire and a physical examination form, as in our previous PFS study ( 3 ) . All
patients had as entry criteria musculoskeletal aching or
stiffness for at least 3 months that involved 3 or more areas,
as well as at least 4 well-defined tender points (3). None had
an underlying condition, including obvious trauma or hypermobility syndrome, to explain their symptoms and signs.
None had evidence of synovitis, muscle weakness, or neurologic abnormality. All the usual laboratory test results were
normal or negative, including complete blood count, Westergren erythrocyte sedimentation rate, muscle enzymes, serum electrolytes, serum calcium, urinalysis, rheumatoid
factor by latex fixation, and roentgenograms of prominently
involved sites.
Two female patients had positive antinuclear antibody tests in low titers (both 1 :80, speckled pattern) without
an underlying cause, including drug or connective tissue
disorder, on followup at 15 and 18 months. Test results for
serum C3 and C4 and antibodies to native DNA, Sm, and
RNP were normal or negative. No patient had clinical
hypothyroidism, and thyroid function tests performed on 12
patients had normal results.
Entry criteria did not include strict counting of a
required number of minor associated criteria (e.g., fatigue,
poor sleep, anxiety) as previously suggested (3). However,
clinical diagnosis quite likely involved some consideration of
these suggested minor criteria.
Normal controls were chosen from among the friends
of patients and were matched for sex, race, and age ( k 2
years). Six normal controls had musculosketal pain in 1 or
more areas for which they did not seek physician consultation.
Tender points were defined as areas of exaggerated
tenderness elicited on moderately firm fingertip palpation of
specific anatomic sites ( 3 ) ; comparatively less pressure was
applied than in adults. Only a response of severe (compared
with mild or moderate) pain, physical withdrawal of the local
part, characteristic body recoil (“jump sign”), or facial
expression of pain qualified as a tender point ( 3 ) .
Differences between patients and controls and between patient subgroups in proportionate frequencies of
dichotomous (yesho) variables were evaluated using the chisquare test with Yates’ correction, as appropriate, or Fisher’s exact test. Continuous variables were analyzed by
Student’s t-test or were dichotomized at critical levels and
subjected to chi-square or Fisher’s exact test. as mentioned
above (1 I).
RESULTS
Frequency of symptoms (Table 2). Diffuse musculoskeletal aching was present in 32 patients (97%); 1
patient consistently complained of stiffness only. Stiffness was present in 79% and subjective soft tissue
swelling in 61% of the patients. Non-musculoskeletal
symptoms were common, including general fatigue
throughout the day in 91%. Although 67% reported not
sleeping well, all patients woke up tired in the morning, implicating nonrestorative sleep. Chronic headaches, not due to sinusitis and often related to tension,
were reported in 54%, numbness in 36%, and irritable
bowel symptoms (altered bowel habits associated with
abdominal pain or discomfort) in 27%. Anxiety and
depression were self-assessed either by patients and
controls or occasionally by their accompanying parent(s); responses were elicited to the questions “do
Table 2. Percent frequency of symptom manifestations in 33
juvenile primary fibrornyalgia syndrome (PFS) patients and 33
matched normal controls”
Symptom
manifestations
Musculoskeletal
Generalized aches and pains
Stiffness
Subjective soft tissue swelling
Non-musculoskeletal
Waking up tired
General fatigue
Anxiety
Poor sleept
Depression
Chronic headaches
Numbness
Irritable bowel symptoms
Juvenile
PFS patients
Normal
controls
91
79
61
15
100
91
70
61
55
54
36
21
3
12
48
15
39
18
9
18
6
3
* Differences were significant at P < 0.005 or lower, except for
anxiety and irritable bowel symptoms, which were significant at P <
0.05.
t Indicates negative response to the question “do you deep well?”
YUNUS AND MAS1
140
Table 3. Frequency (%) of sites of aches, pains, or stiffness in 33
juvenile primary fibromyalgia syndrome patients*
-
Site
Knees
Ankles
Elbows
Lower back
U ppedmid-back
Wrists
Cervical spine
%
Site
67
42
39
33
30
27
27
Trapezius (upper border)
PIP joints (hands)
Upper lateral thigh
MCP joints
Fingers
Thighs (diffuse)
Feet
%
24
24
24
18
18
15
12
* PIP = proximal interphalangeal; MCP = metacarpophalangeal
you regard yourself an anxious or worrying type of
person?” and “do you usually feel depressed or low in
spirit?” respectively. All symptoms were significantly
more frequent among patients than controls.
Sites, duration, and diurnal variation of symptoms. Common sites of aches, pains, or stiffness are
shown in Table 3. Aches and pains were symmetric
(bilateral in more than 80% of affected sites) in 79% of
patients. Total sites of aches and pains among the
patients ranged from 4 to 34 (mean 13; median 12),
compared with 0 to 5 in the normal controls.
Subjective swelling, when reported (61%), involved 1 to 11 sites (mean 8.1 ;median 9), commonly in
or around knees (45% of patients), followed by metacarpophalangeal (MCP) and proximal interphalangeal
(PIP) joints of hands and fingers (18% each), wrists
and ankles (15% each). Numbness, when present
(36%), was described in 1 to 12 sites (mean 8; median
71, commonly in fingers (52%), hands (24%), and legs
(18%).
Duration of aches, pains, or stiffness in patients
ranged from 3 to 122 months (mean 30; median 12).
Only 1 control subject had aches and pains in 3 or
more sites for 3 or more months (but had only 4 tender
points). Four controls had pain in 2 anatomic sites
each, and another in I site. Each PIP or MCPjoint
area (if specified by the patient), a finger, hand or foot,
1 arm, leg or thigh, cervical spine, upper or mid-back,
and lower back were counted as a single site.
Aches and pains were present mostly in the
morning in 45%, morning as well as afternoon or
evening in 35%, no particular time in 13%, and mostly
in the afternoon or evening in 7% of patients. Stiffness
was present mostly in the morning in 75%, lasting 10
minutes to all day (mean 107 minutes; median 60),
mostly in the morning and afternoon or evening in
12.5%, and at no particular time in 12.5%.
Modulating factors. Factors reported to modulate aches, pains, or stiffness are shown in Table 4.
Common aggravating factors were cold andlor humid
weather, physical overactivity or inactivity, anxiety/
stress, and poor sleep. Commonly, a hot shower or
bath, stretching exercises, warm weather, moderate
activity, and massage helped alleviate musculoskeletal
aching or stiffness.
Physical examination. The patients’ mean pulse
rate of 76/minute and systolic blood pressure (BP) of
111 were not significantly different from those of the
matched controls (75 and 104, respectively). However,
the mean diastolic BP of 75 among the patients was
significantly greater than that of 65 among the controls
( P < 0.01), with no correlation between weight and BP
in either group. No patient had definite synovitis,
including objective joint swelling. However, 1 of the
20 patients complaining of soft tissue swelling also
demonstrated mild to moderate diffuse soft tissue
swelling of fingers on examination; results of a bone
scan in this patient were normal.
The most significant finding among the patients
was the presence of multiple tender points (range 531; mean 13; median 12). Although 36% of the normal
controls had 1 or more tender points, none had more
than 4 (range 0 to 4, mean 0.8) ( P < 0.001). Common
sites of tender points are shown in Figure 1. The PIP
and MCP joints of the hands were tender in 3 and in 2
patients, respectively. The normal controls had tender
points, with significantly less frequency than patients,
in the following sites: lateral part of elbows (27%),
sternomastoid muscles (18%), medial part of elbows
(12%), suboccipital areas (6%), posterior iliac crest
(medial aspect), costochondral junctions, and thoracic
spine/paraspine (each 3%).
In view of the median presentation age of 15,
the 20 patients who presented at age 15 or younger
were compared with the 13 patients who presented at
ages 16 and 17. No significant difference was found
between these 2 groups in any variables except height
and weight ( P < 0.05).
Table 4. Frequency (%) of factors reported to modulate aches,
pains, or stiffness in 33 juvenile primary fibromyalgia syndrome
patients
Aggravating factors
YO
Relieving factors
Cold/humid weather
Physical overactivity
Physical inactivity
Anxiet yistress
Poor sleep*
Air conditioningt
88
88
64
45
39
18
Hot showedbath
Stretching exercises
Warm weather
Moderate activity
Massage
General rest
70
85
58
58
55
55
27
* Poor sleep defined as “not sleeping well.”
t Spontaneous response; not included in protocol questionnaire.
JUVENILE PFS
141
-18%
disability, graded as mild in 4 (20%), moderate in 12
(60%), and severe in 4 (20%). At presentation, symptoms were graded as mild in 5%, moderate in 45%, and
severe in 50%. At followup, after a mean period of 18.8
months (range 4-52; median 14), symptoms had generally improved and were absent in S%, mild in 55%,
moderate in 40%, and severe in none ( P < 0.OOl).
Juveniles who slept well at the time of referral did
better at followup than those who did not ( P < 0.05).
The mean number of days lost from school because of
musculoskeletal pain prior to referral was 5.8 t 8.3,
9.4
9.9, and 13 t 17.7, in 3, 6, and 12 months,
respectively. FolIowup disability was not assessed.
*
DISCUSSION
Figure 1. Frequency distribution of common tender points in 33
juvenile primary fibromyalgia syndrome patients; % = percent of
positive patients.
Preceding diagnoses and unwarranted investigations. More than half the patients (55%) did not have a
definite diagnosis on referral. Referral diagnoses included juvenile rheumatoid arthritis in 8 patients,
arthritis in 4, and collagen disease in 1. Only 1 patient
had a diagnosis of fibromyalgia (“fibrositis”). Nearly
half the patients had 1 or more unwarranted investigation(s), including arthrograms in 4, bone scans in 4,
brain scans in 4, myelogram in 1, and spinal tap in 1.
Electroencephalograms (EEGs) were performed on 3
patients because of headaches, numbness, or subjective weakness. One patient was treated with oral
corticosteroids because of a presumed diagnosis of
collagen disease.
Degree of disability, symptom status on followup,
and school absenteeism. Information on these features
was available in 20 juveniles. At presentation, patients
were asked to self-assess their degrees of disability as
none, mild, moderate, or severe, considering how
much their musculoskeletal symptoms interfered with
their normal life activities. All patients reported some
This study, based on 33 juvenile patients and 33
matched normal controls, shows that PFS in juveniles,
like that in adults (1-3,7), is a characteristic nonarticular rheumatic syndrome. Both juveniles and adults
manifest diffuse musculoskeletal aching and/or stiffness with characteristic modulating factors. Manifestations of a systemic disease, e.g., weight loss, fever,
skin rash, and poor appetite, are absent. Physical
examination shows no evidence of synovitis, muscle
weakness, or neurologic abnormality, but multiple soft
tissue tender points are evident at characteristic sites,
as was earlier reported in adult PFS patients ( 3 ) .
Symptoms and tender point sites are consistent and
reproducible at followup. Routine laboratory test results are normal.
Adult PFS and juvenile PFS are similar conditions, although several differences were noted among
the present series of 33 juvenile patients when compared with the 39 adults (age 18 and older) in our
previous series ( 3 ) . Among the juveniles, certain features were more common, i.e., subjective swelling
(61% versus 23%; P < 0.005), ankle pain (42% versus
15%; P < 0.05), and aggravation of pain by overactivity (88% versus 59%; P < 0.05), whereas others were
less frequent, i.e., low back pain (33% versus 69%; P
< 0.005), hand pain (33% versus 69%; P < 0.005),
symptom aggravation by anxiety (45% versus 74%;
P < 0.05), symptom relief by moderate activity (55%
versus 85%; P < 0.05), as well as warmidry weather
(58% versus 85%; P < 0.05), and tender point at
lumbar spine/paraspine area (33% versus 62%; P <
0.05). The different frequency of tender points at the
suboccipital region is explained by a different (and
more sensitive) technique of palpation in our present
series (palpation of rectus capitis posterior insertion,
142
rather than below the superior nuchal line). Overall,
these relatively few differences between juveniles and
adults should be accepted with certain reservations.
Subjective perception of symptoms and their reporting
may be different and less consistent among the younger juveniles compared with the adults.
PFS, either in adults or juveniles, may be
questioned as an entity because no definite physical or
laboratory findings are present, or it may be regarded
as merely an expression of anxiety or depression. Our
psychological studies among adults have shown that
only one-third of patients are disturbed psychologically according to the Minnesota Multiphasic Personality
Inventory, with high scores on the Depression scale
(12,13). Thus, not all PFS patients are unduly anxious
or depressed. Psychological studies are not available
on juvenile PFS at this time, but our general observations suggest that psychological factors in juveniles are
probably similar to adults.
The American Psychiatric Association (APA)
guidelines for diagnosis of psychogenic pain include
absence of adequate physical findings or pathophysiologic mechanisms for pain (14). In PFS, the tender
points on physical examination are usually at specific
sites, are consistent, and are reproducible. As in
tension headaches, muscle spasm, observed in many
patients, probably forms a pathophysiologic basis of
PFS. Tension headaches, present in half of our juvenile patients, have specifically been excluded from the
APA category of psychogenic pain (14).
Anxiety and stress are important contributory
factors for such well-accepted entities as irritable
bowel syndrome (IBS) and tension headaches, both of
which lack definite physical and laboratory findings
and are associated with PFS (3). Conceptually, IBS,
PFS, and tension headache syndrome are similar conditions with muscle spasm as a probable pathophysiologic mechanism common to all (15). PFS and IBS
have many common and overlapping features (15-17).
IBS occurs both in adults and juveniles (17,18). It
appears that multiple factors, e.g., constitutional factors, poor sleep, anxietylstress, subclinical trauma,
and poor posture are contributory in PFS. Objective
sleep EEG studies have shown disturbed non-rapid
eye movement sleep among adult PFS patients (19).
Previous description and prevalence of juvenile
PFS. Bates and Grunwaldt described 62 children aged
3-18 years with “trigger areas” among 85 juveniles
with myofascial pain caused by a variety of underlying
illnesses and injuries (20). These juveniles with nonspecific and heterogeneous myofascial pain are differ-
YUNUS AND MAS1
ent from our PFS patients, since pain and tender
points in these patients were secondary to other conditions, e.g., obvious trauma and infection (20).
Prevalence of juvenile PFS cannot be accurately estimated at this time, but it appears to be common.
Over a period of 18 months, from January 1981 to July
1982, we saw 19 new juvenile rheumatoid arthritis
(JRA) patients, age 17 years or younger at presentation. We saw 15 new juvenile PFS patients who
presented at age 17 years or younger during the same
period. However, if adult PFS patients with symptom
onset under age 16 are accepted as having juvenile
PFS (as is the case in JRA), then the number of
juvenile PFS was 24, compared with 22 JRA patients
with onset age under 16 years.
Clinical features of juvenile PFS. Several features merit discussion. Subjective swelling of soft
tissues may be present in both articular and periarticular locations, leading to a misdiagnosis of arthritis, as
was the case in 8 patients. Except in 1 patient, the soft
tissue swelling was not objectively seen. However, it
is possible that the degree of such swelling is not
severe enough to be detected by physical examination.
This symptom was not related statistically to anxiety
or numbness, but to increased number of pain sites
(P < 0.05). It was also significantly more common
among juveniles who were physically more active ( P <
0.05). Although a history of definite or obvious trauma
was uniformly negative, subclinical trauma or overuse
may thus play a role.
Numbness is another feature which did not
correlate with anxiety. It may be attributed to altered
sensory perception by PFS patients, possibly associated with localized muscle spasm. Neurologic symptoms, including numbness, headaches, and subjective
fatigue, are important features of PFS. These symptoms may contribute to unwarranted investigations,
e.g., electroencephalograms, brain scans, and myelograms, if the syndrome is unrecognized.
Anxiety and depression were assessed by the
patients and occasionally by their parents, as explained earlier. These, as well as other, symptoms
which require subjective assessment (e.g., modulating
factors of aches and pains) are likely to be less reliable
and consistent in juveniles than adults, particularly
among the younger children. Further, patients or their
parents may report anxiety or stress as rationalization
of patients’ symptoms. Psychological studies using
appropriate tools for children may provide a better
evaluation of anxiety, stress, and depression in juvenile PFS.
JUVENILE PFS
Poor sleep is an important symptom and is
likely to contribute to overall aching (19). Although
67% reported that they do not sleep well, all patients
reported fatigue on awakening, implicating nonrestorative sleep (19,21). Morning fatigue may be a more
sensitive indicator of nonrestorative sleep than a general statement of not sleeping well. General fatigue
during the day is also present in nearly all of the
juvenile patients (91%),as in the adults ( 3 ) .
Our previously demonstrated association of irritable bowel syndrome with PFS was also found in
another study (4), and in this juvenile series. Anxiety/
stress is likely to be a common associated factor in
both PFS and IBS.
Symptoms were significantly more common
among the patients than the normal controls. This is in
part due to physician selection of PFS symptoms.
However, all PFS symptoms, e.g., minor criteria (3,7),
were not methodically sought by a physician as entry
criteria, although use of clinical judgement in diagnosis
is likely to have included some of these symptoms.
Although diffuse soft tissue tenderness may be
present in some patients (1,22), localized tenderness at
characteristic sites is more usual on physical examination (Figure 1). Distant radiation of pain from site of
palpation is rare (22), and thus the term “trigger
point” (23) is inappropriate in general, as opposed to
the preferred term “tender point.” One of our patients
presented with pain and tenderness in the temporomandibular joints (TMJ). Fifteen percent had TMJ
tenderness in this study. Such tenderness cannot be
differentiated from that in TMJ syndrome. However, it
is of interest that the most common cause of TMJ
syndrome is functional (24). Some PFS patients do
have features of this syndrome.
Differential diagnosis. Differentiation of other
conditions mimicking juvenile PFS has been fully
reviewed elsewhere (25). Juvenile rheumatoid arthritis
can be distinguished by objective arthritis and other
features (26). Similarly, traumatic arthritis, bursitis,
tendinitis, and muscle sprain are differentiated from
PFS by history as well as the localized nature of these
conditions (in contrast to generalized manifestations in
PFS) (2$,27). Systemic lupus erythematosus is characterized by its clinical and immunologic features (28).
Psychogenic pain is a different entity with bizarre,
highly emotional, and highly inconsistent symptoms;
patients are tender everywhere, even when touched
gently (3). “Growing pains” with musculoskeletal
aching in the absence of an abnormal laboratory test
result (29,30) might have been confused with juvenile
143
PFS in the past, although tender points were not
described in the former. If this term is to be used at all,
only patients with nocturnal limb pain (29-3 1) should
be included in this category. Nocturnal pain did not
occur predominantly in any of our 33 patients. Some
patients with hypermobility of joints have rheumatic
symptoms, including myalgia and arthralgia. A diagnosis of hypermobility can be made by the suggested
criteria of Beighton and Horan (32). However, patients
with hypermobility were excluded from this study.
Children with school phobia may have headaches,
abdominal pain, and, less commonly, vague body
pain, but such symptoms usually occur before school
time (33).
Suggested criteria for diagnosis of juvenile PFS.
All 33 juveniles in this series and none of the matched
normal controls satisfied our previously suggested
criteria for PFS (3,7,27). These criteria include generalized musculoskeletal aching at 3 or more sites for 3
or more months in the absence of an underlying
condition, e.g., arthritis and obvious trauma. Results
of the usual laboratory tests are normal. In addition, 5
or more typical tender points plus 3 of the following 10
features (minor criteria) should be present: 1) chronic
anxiety or tension; 2) fatigue; 3) poor sleep; 4) chronic
headaches; 5 ) irritable bowel syndrome; 6) subjective
soft tissue swelling; 7) numbness; 8) pain modulation
by physical activities; 9) pain modulation by weather
factors; and 10) pain modulation by anxietylstress.
Four tender points will also satisfy the criteria, provided a patient has 5 of the above 10 features.
In this study ofjuveniles, 1 normal control, who
had aches and pains at 5 anatomic sites for 4 months,
had only 4 tender points and 2 minor criteria, and thus
did not satisfy the above criteria. Of the 10 suggested
minor criteria, juveniles were significantly different in
only 3 (increased frequency of pain aggravation by
overactivity and equally decreased frequency of pain
relief by moderate activity in juveniles cancelled each
other). Frequency distribution of these 3 criteria balanced each other, subjective swelling being more
common in juveniles, whereas pain modulation by
anxiety and weather is more common in adults. Independently-derived criteria for juvenile PFS , including
other control conditions with musculoskeletal aching,
e.g., JRA and hypermobility syndrome, will be needed
for a future study.
Whether the onset age, or age at presentation,
under 17 or 18 years should be accepted as criteria for
diagnosis of juvenile PFS is open to discussion. In this
study, no significant difference was found between
144
YUNUS AND MAS1
children who presented at age 15 and younger versus
those who presented at age 16 and 17. Incidentally,
only 1 patient had onset age over age 15 in this study.
As explained in Patients and Methods, it may be
preferable to classify juvenile patients according to
presentation rather than onset age.
Symptoms at followup. Symptoms at followup
generally improved among our patients. Optimal management, including a firm diagnosis, reassurance regarding benign nature (compared with juvenile rheumatoid arthritis), management of stress factors if
present, moderation of physical activity, physical therapy (heat, stretching exercises), simple, non-addictive
analgesics, and a nonsteroidal antiinflammatory agent
also contributed t o less severe symptoms at followup.
Any implication that the pain is “all psychological”
should be avoided. Management of juvenile PFS is
similar t o that of adults (3,7,34), but psychoactive
drugs should rarely be used in children. Long-term
prognosis of juvenile PFS remains unknown, and
needs to be determined in a longitudinal study. From
our experience of adult PFS patients with juvenile
onset, it appears that symptoms of juvenile PFS may
go away in some patients, only t o return later in adult
life.
In conclusion, juvenile PFS is a common and
recognizable condition which should be diagnosed by
its own characteristic features and not merely by
exclusion of other conditions. Diagnosis of juvenile
PFS is important to avoid unwarranted investigations
and improper management.
ACKNOWLEDGMENT
We greatly appreciate the technical assistance of
Barbara Lundeen in this study.
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Erratum
There was an error in Table 2 of an article which appeared in the October 1984 issue of Arthrrtrs and
Rheumatism (Ahles TA, Yunus MB, Riley SD, Bradley JM, Masi AT: Psychological Factors Associated with
Primary Fibromyalgia Syndrome. Arthritis Rheum 27:llOl-1106, 1984). The first two values in the table
column marked “RA” were listed as 44.8 and 48.3. These values should have been 46.6 and 46.6.