Spider angioma

# Overview
Spider angioma or spider naevus is a benign, painless vascular malformation in the skin, formed due to vasodilatory effects of various metabolic and hormonal disturbances. These are small blanchable red papules with capillaries extending radially. They are present mostly on the face, arms and trunk. While multiple, extensive lesions point towards an underlying etiology they can occur solitary without an underlying cause. They are mostly seen in cirrhotic (alcoholism, viral hepatitis) or hyperestrogenic (pregnancy, oral contraceptive pills) patients. Treating the underlying cause is the mainstay of treatment. Facial lesions can be cauterized for cosmetic purposes.

# Historical Perspective
- Spider angioma was first discovered by Dr. Erasmus Wilson, an English Surgeon, in his practice of modern-day dermatology.
- In 1842, he described spider angioma in his book 'A Practical and Theoretical Treatise on the Diagnosis, Pathology, and Treatment of Diseases of the Skin' .
- In 1959, Dr. William Bennett Bean described the lesion in detail in his book 'Vascular Spiders and Related Lesions of the Skin' .

# Classification
Spider angioma may be classified into two groups:
- a. Solitary vascular malformation without any underlying conditions.
- b. Multiple vascular malformations secondary to liver cirrhosis or hormonal imbalances.
Classification based on video dermoscopy:
- a. Network pattern
- b. Looping pattern
- c. Star pattern

# Pathophysiology
- The hypothesized pathogenesis of spider angioma is arteriolar vasodilatory effects of alcohol, substance P, hyperestrogenism, and inadequate hepatic metabolism of steroid hormones.
- In a study of patients with cirrhosis, a higher estradiol/testosterone ratio was found. It is hypothesized that relative estrogen excess mediates vasodilatation and results in the lesions.
- The Mutation in endoglin (ENG) and activin-receptor-like kinase (ALK1) has been associated with the development of Hereditary hemorrhagic telangiectasia, which is associated with increased spider angiomas.

# Causes
- Common causes of spider angioma include liver cirrhosis, hyperestrogenism, and thyrotoxicosis.

# Differentiating spider angioma from other Diseases
- Spider angioma must be differentiated from other diseases that present with similar presentation such as:
Angioma Serpiginosum
Basal Cell Carcinoma
Cherry Hemangioma
Insect Bites
Unilateral Nevoid Telangiectasia
- Angioma Serpiginosum
- Basal Cell Carcinoma
- Cherry Hemangioma
- Insect Bites
- Unilateral Nevoid Telangiectasia

# Epidemiology and Demographics
- The prevalence of spider angioma is approximately 10,000-15,000 per 100,000 individuals in healthy adults and young children worldwide.
- According to a study, in children without liver involvement, 38% had at least one lesion. 8 of 10 children with cirrhosis had at least one lesion, only 4 of 34 children with chronic liver disease had five or more spiders present. There was an increasing trend with the age.
- A study reported around 22% prevalence in normal male children and 30% in normal female children.
- About 33% of the patients with advanced liver cirrhosis have spider angioma.
- A study of 60 pregnant women reported the presence of spider angioma in 32 of them.

## Age
- The mean age was 39.5 years (range: 1076 years).
- Spider angioma is more common in women of childbearing age.

## Gender
- There is no documented study showing gender predilection for spider angioma in an otherwise healthy population.
- However there is an increased incidence in pregnant women, which is attributed to hyperestrogenic states.

## Race
- There is no racial predilection for spider angiomas, but are more visible in light-skinned people.

# Risk Factors
- Common risk factors in the development of spider angioma are those causing hyperestrogenic state (pregnancy, oral contraceptive pills) and liver cirrhosis (Alcohol, Viral hepatitis).
- Higher number of angiomas are seen in patients with Hereditary hemorrhagic telangiectasia.

# Natural History, Complications and Prognosis
- The majority of healthy children and adults with spider angioma remain asymptomatic.
- Common complications of cutaneous spider angioma include bleeding secondary to manipulation.
- There could be relapsing gastrointestinal bleeding in those with internal lesion.
- Prognosis is generally excellent in those with the resolution of underlying etiology.
- Physiological spider angiomas in younger adults usually increase till puberty and then disappear as the age advances.
- In women developing lesions during pregnancy may resolve post-pregnancy.
- In women who take oral contraceptives and present with lesions, they may resolve after the patient discontinues the hormonal preparations.

# Diagnosis

## Diagnostic Criteria
- There is no diagnostic criteria for Spider angioma.

## History and Symptoms
- Spider angioma, when not extensive, can be benign.
- When present extensively it could be due to an underlying cause.
- Alcoholism and higher bilirubin levels were proven to have a correlation for the development of spider angiomas.
- Hyperestrogenic states like pregnancy, oral contraceptive pills, etc could be the underlying cause in young females with no hepatic etiology.

## Physical Examination
- Patients with benign spider angioma usually appear normal.
- Those secondary to underlying cause may have additional symptoms pertaining to the disease.
- A spider angioma has 3 features: a body with small bright red lesions (1mm -10mm) with a central red spot, a leg with radiating thin-walled vessels and surrounding erythema.
- Unusually large presentations with visible pulsatile blood flow have also been reported.
- The blood pressure measures 50 to 70 mm Hg in these small arterioles.
- Spider angiomas are usually present on face, chest and arms in the distribution of Superior vena cava. But unusual presentations with Palpebra, Pleura and subpleura, Esophagus ,and Gastrointestinal tracts  have been reported.

## Diascopy
- Diascopy is the procedure of applying pressure using a glass slide or paper on the lesion to assess for blanchability.
- Pallor upon application of pressure, followed by refilling upon relieving the pressure is characteristic of spider angioma.

## Laboratory Findings
- Laboratory work up for hepatic etiology (Liver function tests, Viral markers), pregnancy (urine pregnancy test), hyperestrogenic etiology (Estrogen and FSH levels) and thyrotoxicosis (T3,T4, and TSH) should be done.

## Electrocardiogram
- There are no ECG findings associated with spider angiomas.

## X-ray
- There are no x-ray findings associated with spider angiomas.

## Echocardiography or Ultrasound
- There are no echocardiography/ultrasound findings associated with spider angiomas as such.
- Ultrasound has a high positive predictive value in identifying the underlying liver cirrhosis.
- Ultrasound may be useful in identifying underlying ovarian tumors.

## CT scan
- There are no CT scan findings associated with spider angiomas.
- CT scan is the most sensitive imaging modality for identifying the underlying liver cirrhosis.
- Ct scan can reveal underlying ovarian tumors.

## MRI
- There are no MRI findings associated with Spider angiomas.

## Other Imaging Findings
- There are no other imaging findings associated with Spider angiomas.

## Other Diagnostic Studies
- Biopsy may be helpful in the diagnosis of spider angioma when the presentation isn't classical. Findings diagnostic of spider angioma include Cutaneous arterial net, Central spider arteriole, Subepidermal ampulla, Star-shaped arrangement of efferent spider vessels, and Capillaries.

# Treatment
- There is no need of treatment for spider angiomas as they cause no imminent harm. Treatment is only directed for cosmetic purposes.

## Medical Therapy
- Treating the underlying cause such as improvement of hepatic function, removal of the agent causing hyperestrogenic state leads to resolution of spider angiomas.

## Surgery
- Surgery therapy is used on facial angiomas for cosmetic concerns.
- Fine-needle electrocautery, 595 nm pulse-dye laser (PDL), 532 nm KTP (potassium-titanyl-phosphate) laser or electro desiccation have been used successfully with only minor scarring.
- 595 nm PDL showed once-treatment cure rates were 100% in the Small-spot-combined-with-large-spot group and 34.8% in the Large spot-group (for skin lesions with a central spider body diameter 1 mm).
- In another study usage of 595 nm PDL showed the improvement rate is 89.4% in a single time of treatment, and 91.0% in twice, 88.4% in 3 times of treatment.

## Prevention
- There are no primary preventive measures available for spider angiomas.