Scleroderma and Raynaud Phenomenon

Chapter 154 Scleroderma and Raynaud Phenomenon

Heather A. Van Mater, C. Egla Rabinovich

Juvenile scleroderma encompasses a range of conditions unified by the presence of fibrosis of the skin. Juvenile scleroderma is divided into 2 major categories, localized scleroderma (LS, also known as morphea), which is largely limited to the skin, and systemic sclerosis (SSc), with organ involvement. Although localized disease is the predominant type seen in pediatric populations, systemic sclerosis is associated with severe morbidity and mortality.

Etiology and Pathogenesis

The etiology of scleroderma is unknown, but the mechanism of disease appears to be a combination of a vasculopathy, autoimmunity, immune activation, and fibrosis. Triggers, including trauma, infection, and, possibly, subclinical graft versus host reaction from persistent maternal cells (microchimerism), injure vascular endothelial cells, resulting in increased expression of adhesion molecules. These molecules entrap platelets and inflammatory cells, resulting in vascular changes with manifestations such as Raynaud phenomenon and pulmonary hypertension. Inflammatory cells infiltrate the area of initial vascular damage, causing further vascular damage and resulting in thickened artery walls and reduction in capillary numbers. Macrophages and other inflammatory cells then migrate into affected tissues and secrete cytokines that induce fibroblasts to reproduce and synthesize excessive amounts of collagen, resulting in fibrosis and subsequent lipoatrophy, dermal fibrosis, and loss of sweat glands and hair follicles. In late stages, the entire dermis may be replaced by compact collagen fibers.

Autoimmunity is believed to be a key process in the pathogenesis of both localized and systemic scleroderma, given the high percentage of affected children with autoantibodies. Children with localized disease often have a positive ANA test result (42%), and 47% of this subgroup have antihistone antibodies. Other autoantibodies seen include rheumatoid factor (RF) (16%) and antiphospholipid antibodies (12%). The relationship between specific autoantibodies and the various forms of scleroderma is not well understood, and all antibody test results may be negative in a child, especially one who has LS.

Classification

Localized scleroderma is distinct from systemic scleroderma and rarely progresses to systemic disease. Within the category of LS there are several subtypes that are differentiated by both the distribution of the lesions and the depth of involvement (Table 154-1). Up to 15% of children have a combination of 2 or more subtypes.

Table 154-1 CLASSIFICATION OF PEDIATRIC SCLERODERMA (MORPHEA)

LOCALIZED SCLERODERMA

Plaque Morphea

Confined to dermis, occasionally superficial panniculus

Well-circumscribed circular area of induration, often a central waxy, ivory-colored area surrounded by a violaceous halo; unilateral

Generalized Morphea

Involves dermis primarily, occasionally panniculus

Defined as confluence of individual morphea plaques or lesions in 3 or more anatomic sites; more likely to be bilateral

Bullous Morphea

Bullous lesions that can occur with any of the subtypes of morphea

Linear Scleroderma

Linear lesions can extend through the dermis, subcutaneous tissue, and muscle to underlying bone; more likely unilateral

Limbs/trunk:

One or more linear streaks of the extremities or trunk

Flexion contracture occurs when lesion extends over a joint; limb length discrepancies

En coup de sabre:

Involves the scalp and/or face; lesions can extend into the central nervous system, resulting in neurologic sequelae, most commonly seizures and headaches

Parry Romberg syndrome:

Hemifacial atrophy without a clearly definable en coup de sabre lesion; can also have neurologic involvement

Deep Morphea

Involves deeper layers, including panniculus, fascia, and muscle; more likely to be bilateral

Subcutaneous morphea:

Primarily involves the panniculus or subcutaneous tissue

Plaques are hyperpigmented and symmetric

Eosinophilic fasciitis:

Fasciitis with marked blood eosinophilia

Fascia is the primary site of involvement; typically involves extremities

Classic description is “peau d’orange” or orange peel texture, but early disease manifests as edema (see Fig. 154-2)

Morphea profunda:

Deep lesion extending to fascia and sometimes muscle, but may be limited to a single plaque, often on trunk

Disabling pansclerotic morphea of childhood:

Generalized full-thickness involvement of skin on the trunk, face and extremities, sparing finger tips and toes

SYSTEMIC SCLEROSIS

Diffuse

Most common type in childhood

Symmetric thickening and hardening of the skin (sclerosis) with fibrous and degenerative changes of viscera

Limited

Rare in childhood

Previously known as CREST (calcinosis cutis, Raynaud phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia) syndrome

Epidemiology

Juvenile scleroderma is rare, with an estimated prevalence of 1/100,000. Localized scleroderma is far more common than SSc in children, by a 10 : 1 ratio, with plaque morphea and linear scleroderma being the most common subtypes. Linear scleroderma is predominantly a pediatric condition, with 65% of patients diagnosed before age 18. After age 8 yr the female : male ratio for both LS and SSc is approximately 3 : 1, whereas in patients younger than 8 yr there is no sex predilection.

Clinical Manifestations

Localized Scleroderma

The onset of scleroderma is generally insidious, and manifestations vary according to disease subtype. The initial skin manifestations of localized disease usually include erythema or a bluish hue seen around an area of waxy induration; subtle erythema may be the only presenting sign (Fig. 154-1). Early edema and erythema are followed by indurated, hypopigmented or hyperpigmented, atrophic lesions (Fig. 154-2). Linear scleroderma varies in size from a few centimeters to the entire length of the extremity, with varying depth. Patients sometimes present with arthralgias, synovitis, or flexion contractures (Fig. 154-3). Children also experience limb length discrepancies as a result of growth impairment due to involvement of muscle and bone. Children with en coup de sabre (Fig. 154-4) may have symptoms unique to central nervous system (CNS) involvement, such as seizures, hemifacial atrophy, ipsilateral uveitis, and learning/behavioral changes.

Figure 154-1 Boy with generalized morphea. Note the active circular lesion (arrowheads) with a surrounding rim of erythema. The largest lesion has areas of postinflammatory hyperpigmentation and depression with an area of erythema on the right. The small lesion (arrow) demonstrates depression due to lipoatrophy.

Figure 154-2 Inactive linear scleroderma demonstrating hyperpigmented lesion with areas of normal skin (skip lesions).

Figure 154-3

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Tags: Nelson Textbook of Pediatrics Expert Consult

Jun 18, 2016 | Posted by admin in PEDIATRICS | Comments Off

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