Clinicals applications of capillaroscopy in dermatology
Psoriasis is an autoimmune disorder which affects the skin and the joints. Its main clinical features consist in the appeareance of red scaly patches on the skin. These patches are areas of chronic inflammation. New skin accumulates at these sites and assumes a silvery-white appearance. Most frequently, plaques appear on the elbows and knees but, in some cases, may affect the scalp and the genital area. The disorder may present itself with a huge variability in severity, ranging from minor localised patches to complete body extension.
Microvascular abnormalities are a characteristic feature of psoriasis and form one of the pathological diagnostic criteria. These changes occur early in the progression of a psoriatic plaque, before there is clinical or histological evidence of epidermal hyperplasia.
Treatment of psoriatic microvessels with a pulsed dye laser (PDL) has been associated with both clinical improvement and clearance of lesions.
Structural vascular abnormalities in plaque skin can be quantified in a non-invasive way with capillaroscopy and investigations can be carried out before and after PDL treatment in order to determine the clinical improvement.
Alterations of the microvasculature are in fact considered to play prominent role in the pathogenesis of psoriasis.
Lichen planus is an inflammatory disease which affects the skin and the oral mucosa. The disorder presents itself in the form of lesions or rashes. The aetiology of lichen planus remains largely unknown. Some cases have been reported of lichen planus-like rashes menifesting as allergic reactions to drugs used to treat high blood pressure, heart disease and arthritis. These lichenoid reactions are referred to as lichenoid mucositis (of the mucosa) or dermatitis (of the skin). Lichen planus has been reported as a complication of chronic hepatitis C virus infection and can occur as a skin manifestation of chronic graft-versus-host disease. Lichen planus affects women more than men (at a ratio of 3:2), and occurs most often in middle-aged adults.
The oral microcirculatory feature of patients with oral lichen planus (OLP) have been extensively reviewed. The presence of characteristic (tortuous, branched) loops has been reported. Capillary density and the diameter of the afferent and efferent ansa are found to be significantly increased in OLP patients compared with controls. The observation of tortuous, branched loops, indicating the angiogenic phenomenon in vivo, is recurrent.
Skin cancer is the most common malignancy of the epidermis. The microcirculatory network of skin tumours can be visualized with non-invasive methods like videocapillaroscopy.
This technique can be used to monitor the neoangiogenic phenomenons at the site of the lesion. Malignant melanoma is characterized by a chaotic distribution of skin capillaries, which appear dilated and form corkscrew-shaped or glomerular structures.
In the transitional area between healthy and cancerous skin, hypervascularization is highly recognizable. Antiangiogenetic therapies are believed become the mainstream pharmacological treatment of malignant melanoma in the near future. In support of this, capillaroscopy provides a reliable method for evaluating the efficacy of treatments.
Videocapillaroscopy is a state of the art technique for the analysis of pigmented skin lesions.
This technique, in combination with apposite softwares, provides a reliable instrument for the differential diagnosis of baenign and malignant skin lesions.