White : Diseases of the Skin - Vascular Disorders

Table of Contents
This Chapter	All Chapters

Gary M. White & Neil H. Cox

Diseases of the Skin

15	Vascular Disorders

LYMPHATIC DISEASE

Lymphedema and chronic edema

Etiology and pathogenesis

Lymphedema occurs in several situations. In many tropical countries, the commonest cause is infection by filariae, which cause lymphatic obstruction leading to elephantiasis of the legs, scrotum, penis, and vulva.

In developed countries, a minority of cases are due to an inherited predisposition with onset expected at various ages in childhood or young adult life (e.g. Milroy disease); such cases are often severe, due to anatomic abnormalities of the lymphatics. It is also an early feature in Turner syndrome.

Figure 15.54 Lipodermatosclerosis. This patient showed three manifestations of venous insufficiency: lipodermatosclerosis, atrophie blanche, and an ankle flare.

Figure 15.55 Lymphedema from cardiomyopathy causing lymphangiomas of the pubic area. This may also occur on the scrotum.

More commonly, lymphedema of the legs is the end result of chronic edema (of various causes) combined with poor mobility in older patients, especially in women; the classic pattern has been termed ‘armchair legs'. Many now feel that any chronic edema state, even if primarily cardiac, will involve at least some component of lymphedema (Fig.15.55).

Other causes include lymphatic obstruction of a limb (arm or leg) due to tumor, lymphadenectomy, or radiation therapy to lymph nodes.

Clinical

Mild lymphedema of the legs may be indistinguishable from edema of cardiac causation but is refractory to diuretic therapy. With chronicity, redness of the legs may become prominent, and warty or nodular lesions develop (Fig.15.56). A chronically enlarged, edematous leg or legs with a verrucous or cobblestoned surface is characteristic (Fig.15.57). Stemmer sign, thickening of the skin over the dorsal toes, is highly characteristic. In its most advanced chronic stages, the skin of the leg is ‘mossy', cobblestoned, or verrucous, a pattern termed elephantiasis nostras verrucosa.

Figure 15.56 Stasis dermatitis aggravated by saphenous vein grafting. (a,b) Note the edematous leg, papillomatous thickening, and the vein graft scar.

Figure 15.57 Elephantiasis nostras. (a) Note greatly thickened leg with distortion of features. (b) Close-up view shows multiple papules and nodules.

Figure 15.58 Bulla formation in the setting of stasis dermatitis. The rapid onset or exacerbation of leg edema may induce bulla formation. .

Bullae may occur (Fig.15.58) and are more likely to form if the edema develops or increases in severity acutely. A reticulate pattern of ridges on the lower leg in lymphedema appears to follow thermal damage, similar to the patterning in EAI, and has been termed lymphedema ab igne.

Recurrent streptococcal cellulitis is a frequent and important complication of chronic edema or lymphedema, and requires aggressive therapy (Fig.15.59).

Ulceration may occur, and chronic weeping from such areas is difficult to manage.

Figure 15.59 Bacterial cellulitis in the setting of chronic lymphedema.

Differential diagnosis

This includes pure cardiac edema and pretibial myxedema, plus rare disorders such as lichen myxedematosus; the main diagnostic issue is between the different causes of lymphedema.

The redness of chronic edema may be confused with cellulitis but is typically bilateral and is not associated with pyrexia or malaise; it commonly causes diagnostic difficulty in determining whether a true episode of cellulitis has settled.

Treatment

Elevation of the legs, support hose, and antibiotics for infection (aggressive treatment with intravenous penicillin) are all helpful. Daily compression may be useful for severe cases. A ‘short stretch' bandage is best in lymphedema, as compression is only effective during activity, as this stimulates lymph flow. A high-potency topical steroid may decrease the pebbly thickening. Acitretin, an oral retinoid, may be tried for the verrucous change.

For those with upper limb lymphedema, and to a lesser extent for the legs, massage treatments to each quadrant of the trunk in turn (the area adjacent to the affected limb last) can be helpful.

PRACTICE POINTS

•	It is often stated that cardiac edema can be pitted by pressure but that lymphedema cannot; this is not correct. Pitting occurs in early lymphedema but becomes less possible with chronicity as fibrosis occurs.
•	The redness of chronic edema may be confused with cellulitis but is typically bilateral and is not per se associated with pyrexia or malaise; cellulitis is a common complication of lymphedema but is rarely symmetric.

Lymphangioma

Just as blood vessels may dilate, forming hemangiomas, lymphatic vessels may dilate, forming lymphangiomas. Grouped vesicles, with onset from birth to adulthood, are characteristic of lymphangioma circumscriptum (Fig.15.60). The fluid may be blood-tinged or show a blood–fluid line. These lesions often communicate with deeper lymphatics, which may explain why therapy involving simple destruction commonly leads to recurrence.

Figure 15.60 Lymphangioma. These lesions represent dilated lymphatic vessels.

Figure 15.61 White avascular spots. These white spots are most commonly seen on the arms of young women. They represent a relative decrease in blood content and are entirely benign.

No treatment is necessary. Simple destruction or surgical excision may be tried. The CO₂ laser or, if the fluid is blood-tinged, the tunable dye laser, can be used.