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What is This Vascular Lesion?

What is This Vascular Lesion?

Patient Presentation

Derm DXA 63-year-old female presented with an erythematous rash on her right upper arm and forearm. The lesion began at the age of 18 years and initially involved only her right forearm. Over several years, the lesion extended proximally to also involve the right upper arm. The lesion was asymptomatic and blanched with pressure.


What is your diagnosis?


DIAGNOSIS: Unilateral Nevoid Telangiectasia

Unilateral nevoid telangiectasia is a benign vascular lesion that was first described by Alfred Blaschko in 1899.1 In 1970, Victor J. Selmanowitz proposed the actual term unilateral nevoid telangiectasia.2 Jonathan K. Wilkin later proposed another more descriptive term — unilateral dermatomal superficial telangiectasia.3 Both of these terms are commonly used today.


There are two forms of unilateral nevoid telangiectasia: congenital and acquired. The congenital form is more commonly seen in men, whereas the acquired form is more prevalent in women.1 In the acquired form, onset may occur anytime from childhood to early adulthood with or without evidence of a co-morbid condition or coincide with an elevation in hormone levels, such as at puberty or during pregnancy.1,4-8

Unilateral nevoid telangiectasia appears to be a rare clinical entity, as fewer than 100 patients have been described in the literature; however, the number of reported individuals may not accurately reflect the actual incidence of this condition.9 In 1983, Wilkin et al summarized the 46 patients to that date; of these individuals, only 11 were of the congenital form.1 A familial case was also reported.1

Clinical Presentation

Most patients with unilateral nevoid telangiectasia are asymptomatic. One patient reported mild pruritus; however, this is the exception.10

Derm DXDerm DXMorphologically, the condition exhibits partially to completely blanched, erythematous, macular lesions (Figures 1 and 2, left to right). They are arranged in a linear pattern, usually along a dermatome or following Blaschko’s lines. The presence of an ‘anemic halo’ may also be seen surrounding the telangiectasias. Lesions may become more prominent during pregnancy.10-12

As per the descriptive nomenclature, the condition is unilateral. The vascular lesion appears to have a predilection for the face, neck, shoulder, arm and chest,13 although involvement of the lower extremity was reported in a pediatric patient.7


Histological findings can help to confirm the suspected diagnosis of unilateral nevoid telangiectasia. Biopsy specimens reveal multiple, dilated, thin-walled vessels in the upper dermis.10-12 However, in most individuals, the diagnosis is based on the clinical presentation and morphology of the lesions.


The pathogenesis of unilateral nevoid telangiectasia is unclear. There is a probable role for both genetics and environmental factors in the development of the unilateral lesions. Unilateral nevoid telangiectasia has been shown to occur in healthy patients as well as those with proven pathologic disease. In addition, it may be present at birth.

A 22-year-old pregnant woman with acquired unilateral nevoid telangiectasia noted that the number of lesions and the involved areas had increased during her second month of pregnancy.14 The investigators demonstrated the presence of increased levels of estrogen and progesterone receptors in the involved skin.14 However, multiple biopsy samples in other patients with unilateral nevoid telangiectasia were negative for the presence of either estrogen or progesterone receptors.8-10,15

The development of unilateral nevoid telangiectasia has also been temporally associated with states of increased estrogen levels. Hence, researchers have suggested that the condition may be related to hormonal effects at the level of the blood vessels in the involved skin. It has been proposed that the involved areas have increased levels of estrogen receptors and that the involved vessels are affected when increased levels of estrogen are present in serum.9

One woman with unilateral nevoid telangiectasia noticed that her telangiectasias decreased in redness when she started oral contraceptive therapy.1 Coinciding with this change, the investigators noted a decrease in her estrogen levels after initiating treatment with a low-dose contraceptive.1

The linear pattern of unilateral nevoid telangiectasia is described as either ‘dermatomal’ or as ‘following Blaschko’s lines.’ Hence, the distribution of the telangiectasias suggests a congenital predisposition of certain areas to develop the lesions. Somatic mosaicism, caused by mutations that occur during development that result in distinct cell populations existing in a single individual, is the most common explanation. Blaschko’s lines are the pathways that are traveled by these cells during embryologic development.7

Differential Diagnosis

Serpiginous angioma is the main differential diagnosis when suspecting a unilateral nevoid telangiectasia.4,10-11 Histologically, serpiginous angioma is characterized by clusters of dilated vessels with thickened walls in the dermal papillae. It may present with unilateral or bilateral skin involvement and typically involves the lower extremities of young women.3

Associated Conditions

The acquired form of unilateral nevoid telangiectasia is most often associated with physiologic states of elevated estrogen. It is most commonly observed in women at puberty and during pregnancy.1,10 In contrast, men with acquired unilateral nevoid telangiectasia often have chronic liver disease, secondary to alcoholism and associated with cirrhosis.1 Hepatitis C virus infection has also been reported in association with acquired unilateral nevoid telangiectasia with or without evidence of active liver disease.9 Although a co-morbid condition is often present, unilateral nevoid telangiectasia has also been reported in both healthy men and children.4-8

Other skin conditions have been reported to occur in association with unilateral nevoid telangiectasia. One patient with the congenital form presented with a new lesion that had developed within her congenital lesion.16 The patient denied any trauma or insect bites to the area, and no medications were being taken. Excision of the lesion revealed a pyogenic granuloma that had presented as a solitary red papule.

Unilateral nevoid telangiectasia was observed to co-exist and overlap with Becker’s melanosis in another patient.17 The 46-year-old man sought treatment for a slowly progressive red rash on his left chest and upper arm that had developed over the past several years. He was unaware of another large hyperpigmented, hypertrichotic patch present on his upper left back that was observed to overlap in areas with the erythematous lesions of his left chest. The presence of both of these lesions was perplexing, as unilateral nevoid telangiectasia is associated with increased estrogen levels while Becker’s melanosis has been shown to have an increased presence of androgen receptors.17

Derm DXSee Table 1 (left) for a list of associated conditions.


Unilateral nevoid telangiectasia may be treated with a pulsed dye laser, primarily for cosmetic concerns. In one study, six patients were given treatments with the pulsed dye laser at 4- to 6-week intervals.18 Significant lightening of the vascular lesion was achieved in all patients after two to four treatment sessions. The only adverse effect was pigmentary changes, either hypopigmentation or hyperpigmentation, which were transient. During the follow-up period, recurrence of the lesions was not observed. Hence, this treatment was considered to not only be safe, but also effective for all ages and areas of the body.18


Unilateral nevoid telangiectasia may be congenital or acquired. The vascular lesion is generally asymptomatic, blanches with pressure, occurs in a linear pattern and has a unilateral distribution. The acquired form is most often associated with physiologic states of increased estrogen levels and in patients with liver disease. The definitive pathogenesis remains to be established. Treatment with the pulsed dye laser is an effective and beneficial modality for cosmetic concerns.

Ms. Paul is with the University of Texas Medical School at Houston in Houston, TX. Dr. Cohen is with the University of Houston Health Center, University of Houston, The University of Texas M.D. Anderson Cancer Center, and the Department of Dermatology at the University of Texas Medical School at Houston in Houston, TX.

Disclosure: The authors have no conflicts of interest or financial disclosures to report.

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