Red swollen legs

Definition

Red swollen legs are characterized by edema and inflammatory erythema, behind these symptoms several underlying disorders can appear. It can be either acute or chronic.

Epidemiology

Depends on the underlying condition, the most frequent are:

Erysipelas: prevalence around 1100/100.000 per year.
Deep vein thrombosis: incidence 80 cases per 100.000 annually, prevalence 1 case per 1000 population.
Superficial thrombophlebitis: 125.000 cases a year.

Aetiology & Pathogenesis

Erysipelas: see chapter 2.2.4.
Deep vein thrombosis.
Superficial thrombophlebitis.
Contact dermatitis.
Borreliosis.

Increasing age and compounding morbidity, such as reduced mobility following a stroke, arthritic changes, obesity, and generalised frailty are promoting factors. Predisposing factors include potential site of pathogen entry (e.g., ulceration, tinea pedis, and traumatic wounds), chronic oedema, lymphoedema, CVD, and obesity.

Predisposing factors: prolonged standing or sitting with the calf-muscle pump inactive, female gender, obesity, older age, post-thrombotic syndrome.

Localisation & Symptoms

Redness and swelling due to oedema or fibrosis that affects one or both legs and/or feet up to the thighs, accompanied by warmth and tenderness in the area, depending on the underlying condition. Superficial and deep vein thrombosis as well as erysipelas are painful, whereas contact dermatitis is itchy.

Classification

Acute disorders: erysipelas, necrotising fasciitis, superficial thrombophlebitis, deep-vein thrombosis (DVT), stasis and contact dermatitis, traumas and septic arthritis.
Chronic disorders: chronic oedema, lymphoedema, pretibial myxedema, CVD manifesting with stasis eczema, venous leg ulcers and lipodermatosclerosis.

Laboratory & other workups

Inflammatory markers: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), D-dimer and white cell count for vein thrombosis. Microbiology of any fissures or erosions in the skin should be considered before antibiotics are started. Wells score to stratify DVT risk into low-, moderate-, or high-risk categories. Ultrasound with echocolor Doppler to confirm or exclude vein thrombosis.

Dermatopathology

Is based on the underlying disorder.

Course

Red swollen legs can be an acute or a chronic disorder depending on the pathological process.

Complications

Age-related poly-morbidity is increasing as people are living longer and adopting prolonged unhealthy lifestyles. Complications may result from bacterial or fungal infections ulceration, traumatic wounds, stage III lymphoedema, venous insufficiency and obesity.

Diagnosis & Differential diagnosis

Acute disorders include skin infections (erysipelas, stage I and stage II borreliosis, cellulitis and necrotizing fascitis), joint infections (arthritis) all of which are associated with fever. Skin infections are detailed in chapter ‘Erysipelas’. The most crucial early characteristic symptom is a disproportionate level of pain compared with the presenting symptoms.
Deep-vein thrombosis (DVT) manifests with leg pain, swelling, tenderness, increased temperature, pitting oedema, and prominent superficial veins. DVT occurs in association with several risk factors, including postoperative immobilization, long-haul travel and age, male gender, genetic or acquired thrombophilia, obesity, acute medical illness, cancer, and pregnancy.
Acute onset allergic contact dermatitis is common, especially in the setting of stasis dermatitis and often related to hypersensitivity reactions to topical medications.
Dermatitis manifests with an acute eczematous reaction with erythema and vesiculation followed by desquamation. Itch may be severe.
Superficial thrombophlebitis is an inflammation of a superficial vein due to a blood clot and is believed that the cause is a disequilibrium of the hemostasis. Chronic disorders include CVD where venous hypertension results in localised oedema that traps leukocytes and neutrophils in the tissues. Tissue damage eventually results in the development of fibrosis, dermatitis and ulceration.
Lipodermatosclerosis is an inflammation of subcutaneous fat, and presents as fibrosed, rigid, red or brown skin, typically affecting the medial aspect of the calf. The subcutaneous tissues may become firm and depressed, and if circumferential damage occurs, could eventually result in an ‘inverted champagne bottle’ effect.
Stasis eczema is a consequence of CVD, with skin becoming itchy, red, swollen, dry and flaky, scaly or crusty, and weeping. The severity (oedema due to liver cirrhosis, nephrotic syndrome and heart insufficiency or dysbalance of protein metabolism) of these symptoms can fluctuate between periods of improvement and periods of increased severity.

Prevention & Therapy

See the respective diagnoses.

8.8 Red swollen legs