OVERVIEW
Generalized idiopathic capillary dilatation is a rare condition characterized by widespread dilatation of small veins and capillaries in the skin of the extremities and trunk, without other skin damage. The etiology of the disease is unknown.
Causes
The cause of this disease is unknown.
Symptoms
It occurs in women aged 40 to 50 years. Skin manifests as extensive linear capillary dilatation. It begins in the calves and may extend to the thighs, abdomen, buttocks, and upper extremities. They may be generalized, unilateral, or confined to the skin of a large area (e.g., lower limbs, upper limbs, trunk), or distributed along the dermal nerve course, scattered or fused with each other. It may also present as small hemangiomas. In some patients, the conjunctiva and oral mucosa may also be involved, but there is no systemic lesion or hemorrhage.
Examination
Histopathology: Dilated, congested capillaries in the upper dermis with defective walls composed only of endothelial cells. Histochemical staining for alkaline phosphatase activity in the arterial portion of the vascular collaterals is negative, indicating that the dilated capillaries are the venous portion of the capillary collaterals.
Diagnosis
The diagnosis is made on the basis of dilated veins and capillaries occurring in the skin of the extremities and trunk, widely distributed without other damage, combined with dermatopathologic examination.
Differential diagnosis
Differential diagnosis should be made with the following diseases
1. Atypical hereditary hemorrhagic capillaritis
It tends to occur in the upper part of the body, with wide distribution, symmetry, and bleeding tendency.
2. Capillary dilatation with systemic diseases
There are manifestations of various systemic primary diseases, and histochemical staining shows active alkaline phosphatase in the endothelial cells of terminal small arteries and arterial ends of capillary loops.
Treatment
No specific treatment is available. Laser therapy may be effective.