Childhood
Dermatomyositis:
Serial
Microvascular
Studies
Richard
M. Silver,
MD, and Hildegard
R. Maricq,
MD
From the Division of Rheumatology, Department of Medicine, Medical University of South Carolina, Charleston
ABSTRACT. Childhood dermatomyositis is an inflam-matory condition affecting the skin and muscles that is
often associated with a small vessel vasculopathy. Ac-cording to previous retrospective studies, it is suggested that the severity of the vasculopathy is related to the course of the disease. Sequential in vivo nailfold micros-copy was used to assess the frequency and the degree of vasculopathy in nine children with dermatomyositis. The
degree of morphologic changes in the nailfold capillary
bed was shown to correlate with the clinical course. The technique of nailfold capillaroscopy may prove to be a
clinically useful, noninvasive means of early prognosis.
Pediatrics 1989;83:278-283; dermatomyositis.
ity of the vasculopathy portends the likelihood of persistent morbidity, however.3
We have used the technique of in vivo nailfold capillary microscopy, a noninvasive means of
as-sessing microvascular abnormalities, to assess the frequency and the degree of vasculopathy in
child-hood dermatomyositis. In this report, we describe
serial observations of nailfold capillary abnormali-ties in nine patients with childhood dermatomyo-sitis. The degree and type of initial capillary
abnor-malities and the persistence of microvascular
pa-thology were found to correlate with the clinical course and outcome.
Childhood dermatomyositis is a multisystem dis-ease characterized by inflammation of the skin and
muscles. The childhood variety of dermatomyositis is associated with a vasculopathy affecting capillar-ies, venules, and small arterioles.1 Immunoglobulin
M, C3d, and fibrin are present in the microvascular
lesions.2’3 The complement membrane attack corn-plex in the arterioles and capillaries of muscle
bi-opsy specimens has been shown in recent studies.4
Thus, there is strong evidence of an immune-me-diated microangiopathy underlying the
pathogen-esis of childhood dermatomyositis.
The clinical course of the disease is highly van-able, with some patients having a chronic relapsing
or persistent disease, whereas others have a
mono-cyclic, nonprogressive course. Authors of two recent retrospective reviews could not delineate clinical factors that identified patients who were to
expe-nience a chronic course.5’6 A retrospective study of
muscle biopsy specimens suggested that the
sever-Received for publication Dec 29, 1987; accepted Feb 24, 1988. Reprint requests to (R.M.S.) Division of Rheumatology and Immunology, Department of Medicine, Medical University of South Carolina, 171 Ashley Aye, Charleston, SC 29425.
PEDIATRICS (ISSN 0031 4005). Copyright © 1989 by the American Academy of Pediatrics.
MATERIALS
AND
METHODS
Patients
The study group consisted of nine children with
childhood dermatomyositis who had two or more in vivo nailfold capillary microscopic studies during
the course of their illness. Two other children oh-served in our clinic had had only one nailfold
cap-illary examination and were excluded from this
study. All nine children fulfilled the criteria for
definite or classical dermatomyositis.7 The major clinical features of the study patients are outlined in the Table. There were seven girls and two boys. Age at time of diagnosis ranged from 1.5 to 11 years,
with a mean of 5.9 years. Seven of the nine patients
have had a persistent disease course, defined as mild to severe exacerbations and remissions for
greater than 1 year following disease onset, and six
have required chronic steroid and/or
immunosup-pressive therapy. Six of the seven patients with a persistent disease course have had cutaneous ulcer-ations (4/6) and/or calcinosis cutis (4/6). Two of the nine patients had a transitory disease course, defined as recovery beginning within 6 months of diagnosis and reaching completion within 1 year of diagnosis, and neither have required long-term
TABLE. Clinical F eatu res of Patien ts With Childhood Dermatomyositis*
Patient Age When Sex Course Interval From Di- Cutaneous Calcinosis Duration of
Diagnosed agnosis to Capil- Ulcers Follow-up
(yr) lary Study (yr)
S.D. 7 F Persistent 5 d + + 4/12
V.R. 11 F Transitory 2 d - - 48/12
J.E. 4 M Persistent 3 d + - 1/12
J.T. 11 M Persistent 2 d + - 18/12
G.C. 4 F Persistent 2 d - - 2/12
E.G. 4 F Transitory 2 mo - - 1’%2
N.K. 4 F Persistent 5 yr - + 9
B.H. 7 F Persistent 9 mo - + 5’/12
L.B. 1#{189} F Persistent 4#{189}yr + + 5/12
* Symbols: +, present; -, absent.
Fig 1. a, Nailfold capillary pattern in healthy subject. b, Thrombotic capillaries and capillary hemorrhages in patient J.T. two days after diagnosis of childhood dermatomyos-itis. c, Extensive loss of capillaries along distal edge of nailfold 6 weeks later. d, Giant capillaries adjacent to avascular areas and “bushy” formations approximately 3 months after diagnosis.
course had cutaneous ulceration or calcinosis cutis. Duration of follow-up ranged from 1.3 to 9 years,
with a mean follow-up period of 4 years. There is no difference in duration of follow-up for the two
types of disease courses, persistent and transitory.
Nailfold
Capillary
Microscopy
In vivo nailfold capillary microscopy was per-formed as previously described, whereby scoring of capillary abnormalities is based on capillary loop
dimensions and the extent of avascularity of
nail-fold capillary beds.8’#{176}Briefly, capillaries at the edge of the nailfold of each finger were observed with a stereomicroscope (magnification x12 to 14) after
this site was covered with grade B immersion oil.
Wide-field photographs were obtained using a 35-mm single-lens reflex camera and Kodachrome 25
film.9 At each examination, the following features
of microvascular angiopathy were sought and re-corded: thrombosis and hemorrhage, areas of avas-cularity (>0.4 mm2), enlargement of capillaries
(100- to 150-sm loop width), giant capillary loops
(>150-sm loop width), disorganization of the nor-mal distribution of capillaries, and “bushy”
capil-lary formation.’#{176} All ten fingers and the dorsum
and palm of the hands were examined. The interval from the time of diagnosis to the initial in vivo capillary microscopic study ranged from two days to 5 years. Five of the nine patients had their initial capillary study performed within 1 week of
normal compared with top right but still show microan-giopathic changes. Bottom left, Reappearance of Gottron papules approximately 10 months later. Bottom right, The nailfold capillary bed approximately 10 months later has appearance similar to that seen on first visit.
capillary study at 2 months, 9 months, 4.5 years, and 5 years, respectively, after the diagnosis. The total number of capillary studies performed on in-dividual patients ranged from two to 1 1, with a mean of 4.8. Serial capillary examinations spanned a period of 9 months to 6 years.
RESULTS
During the period of observation, dynamic
changes in the microvasculature were noted in all
Fig 2. Top left, Numerous Gottron papules during active phase of disease in patient G.C. Top right, Appearance of nailfold capillary bed. Numerous “bushy” formations and considerable avascularity. Middle left, Gottron pap-ules have almost disappeared during clinical remission.
Middle right, Nailfold capillaries have returned toward
nine patients with childhood dermatornyositis. We have not observed such morphologic abnormalities
nor such dynamic changes in the nailbed capillaries
of children without dermatomyositis, children with
systemic lupus erythematosus, or children with ju-venile rheumatoid arthritis.’1
Five of the nine study patients with childhood
dermatomyositis underwent nailfold capillary
the course of the disease (Table). The earliest changes seen in the nailfold capillary bed consisted of thrombosis and hemorrhage (Fig 1). In the most severely affected cases, thrombosis and hemorrhage
were followed by extensive loss of capillaries in a
wide band along the edge of the nailfold (Fig 1).
The dynamic nature of the vasculopathy affecting the nailbed capillaries was seen in follow-up studies.
Early changes of hemorrhage and thrombosis
evolved during several months to the characteristic capillary pattern of childhood dermatomyositis, ie, giant capillary loops and “bushy” capillary
forma-tions. Such changes in capillary morphology were
often noted to occur adjacent to areas of
avascular-ity (Fig 1).
Capillary changes were not always unidirectional, however, as seen by serial observations. As shown by patient G.C., nailbeds with “bushy” capillaries (Fig 2, top right) at times returned toward normal (Fig 2, middle right). This suggests that “bushy” capillaries may represent an attempt at capillary
neoformation. Subsequent observation of the same
nailbed revealed the recurrence of “bushy” capillar-ies, perhaps the result of additional microvascular injury and attempted repair (Fig 2, bottom right).
In all seven cases in which childhood
dermato-myositis had a chronic disease course, the nailbed
capillaries never assumed a completely normal
mor-phologic appearance. In such cases, bushy capillary formation was accompanied by variable degrees of capillary loss and avascularity, and, in nailbeds that appeared nearly normal, additional microvascular
abnormalities later developed. It is of note that
nailbed capillary changes paralleled the cutaneous feature, Gottron papules, in two patients (V.R., G.C.). The presence of Gottron papules is shown
(Fig 2, top left) followed by apparent healing (Fig 2, middle left) and subsequent reappearance of the
Fig 3. Left, Extensive avascular area and disorganization of nailfold capillary bed in patient E.G. 2 months after diagnosis of childhood dermatomyositis. Right, Normal
lesions (Fig 2, bottom left). These observations of
cutaneous changes correspond in time to the nailbed capillary changes observed in a single digit (Fig 2, right).
In contrast, the two patients with childhood
der-matomyositis who had a transitory disease course
(V.R., E.G.) were characterized by less severe
cap-illary changes and only minor or no hemorrhagic and thrombotic features at the onset (Fig 3, left). Furthermore, in both patients, complete return to
a normal nailfold capillary status occurred (Fig 3, right). As seen in Fig 4, the return to normal capillaries was accompanied by resolution of the Gottron papules; motor strength and muscle en-zymes also returned to normal and have remained
normal.
DISCUSSION
Although the cause of childhood dermatomyositis
is unknown, there is clinical and histopathologic
evidence of an underlying microangiopathy. The
severity of microvascular lesions observed in pre-treatment muscle biopsies has been shown to cor-relate with the outcome of the disease. Crowe et al3
found that loss of the muscle capillary bed, muscle infarction, noninflammatory endarteropathy, and
lymphocytic vasculitis were associated with
chro-nicity.
Morphologic abnormalities of the nailfold
capil-lary bed are well documented in childhood derma-tomyositis,’2 and, in retrospective studies, the
nail-fold capillary abnormalities have been correlated
with the microangiopathy present in muscle biopsy specimens,’3 as well as with the more severe clinical courses of the disease.’4 Interpretation of these studies has been tempered by the retrospective design as well as by the time intervals between
Fig 4. Top, Gottron papules in patient V.R. Bottom, Follow-up 32 months later. Gottron papules have disappeared. Patient has been in remission for 19 months.
nailfold capillary examinations and muscle
biop-sies.
According to our data, the degree of morphologic changes in the nailfold capillary bed correlates with the clinical course. Children with persistent disease, often complicated by ulcerative cutaneous lesions
and calcinosis, had relatively severe microvascular abnormalities that fluctuated to some degree but
never returned to normal. These microvascular
ab-normalities were detected within 1 week of
diag-nosis in four of seven children who ultimately had
a persistent disease course. In contrast, the two
patients in whom the disease was transitory or monocyclic had less severe capillary alterations and a return to a completely normal nailfold capillary bed. In two patients in whom serial observations of Gottron papules were made, the capillary nailbed
changes were found to parallel the Gottron papules.
Thus, nailfold capillary findings may reflect the widespread microangiopathy that characterizes childhood dermatomyositis. Bowyer et al’5 recently described cutaneous vasculopathy in three cases of
under-lying childhood dermatomyositis and scleroderma in which microvascular injury is a primary event. Morphologic abnormalities of nailfold capillaries
are well described in adult scleroderma, and the
extent of capillary loss (avascularity) has been shown to correlate with the severity of disease.’6
There is less known about nailfold capillaries in
childhood scleroderma, which is relatively rare.
Our study was limited by the small numbers of
patients, particularly in the category of transitory
disease course, and additional patients must be studied to confirm our observations. These findings do corroborate the retrospective observations of
others, in which nailfold capillary changes are cor-related with clinical outcome.’4 Furthermore,
nail-fold capillary abnormalities are present early in the
disease course of childhood dermatomyositis
ac-cording to our data. If confirmed by the study of more patients, the technique of nailfold capillaros-copy may prove to be a clinically useful,
noninva-sive means of early prognosis. As previously sug-gested,6 the availability of reliable prognostic data
at diagnosis should prove useful in selection of
optimal therapy and in patient and family counsel-ing.
ACKNOWLEDGMENTS
The authors acknowledge the technical assistance of V. Nair and thank Dr G. Young for referring patients for the study.
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