|
Acrodermatitis chronica atrophicans, the characteristic cutaneous
manifestation of late Lyme borreliosis, typically occurs in elderly
women.
Visit:
Lyme Disease (Lyme Borreliosis)
;
Erythema
chronicum migrans
It is a
chronic manifestation of infection by Borrelia burgdorferi . B. afzelli is the predominant etiological agent.
Clinical
presentation:
Image Link
Early inflammatory stage is characterized by diffuse or localized
erythema. It gradually spreads on the extensor surfaces of the
extremities and areas around joints. Later there is gradual atrophy of
the skin with loss of appendages. Sclerodermatous patches and linear
fibrotic bands may be present over ulna and tibia.
Histological
features:
Early stages of the disease show superficial and deep inflammatory
cellular infiltrate in the dermis. The moderately dense infiltrate is
composed of lymphocytes and some histiocytes and plasma cells.
Prominent vascular channels together with telangiectasia may be
present.
In some cases
there is a superficial band-like infiltrate of inflammatory cells with
subepithelial thin zone of collagen.
Vacuoles are
sometimes noted in the upper dermis.
As the disease
progresses there is atrophy of the dermis together with loss of
elastic fibers and pilosebaceous follicles and atrophy of subcutis.
Other changes
include epidermal atrophy and loss of rete ridges, features resembling
lichen sclerosus et atrophicus.
In the
sclerodermatous patches are characterized by dense dermal sclerosis.
This process can
be told to be active by the density of the lymphoplasmacytic
infiltrate and can be considered to be long standing by the extent of
fibroplasia, thick collagen bundles being aligned mostly parallel to
the skin surface, sclerosis being evident in the deep reticular
dermis, and telangiectases being prominent in the upper part of the
dermis.
Juxtra-articular
fibrous nodules are characterized by broad bundles of homogeneous
collagen in the upper subcutis. Perivascular and interstitial
inflammatory infiltrate is present.
Differential
diagnosis: Morphea: ACA shows atrophy of collagen and elastic tissue as well as
hypertrophic basophilic elastic tissue; whereas in morphea, sclerosis
and polarizing elastic tissue are prominent. Graft-versus-host-like
reactions may be present in both dermatoses.
|
