Unilateral nevoid telangiectasia (UNT) is a cutaneous condition consisting of congenital or acquired patches of superficial telangiectasias in a unilateral linear distribution. Described in 1899 by Blaschko, its segmental pattern suggests a mechanism of somatic mosaicism apparent early in life or unmasked in states of relative estrogen excess, such as that in pregnancy or in chronic liver disease.
In acquired unilateral nevoid telangiectasia, the telangiectasias may improve as the estrogen levels decrease, such as following pregnancy or with the discontinuation of oral contraceptives. In other cases of acquired or congenital unilateral nevoid telangiectasia, the lesions persist.
Cutaneous lesions are asymptomatic and may go unrecognized. Inquiry into possible stimulus for development may include relation to puberty, pregnancy, contraceptive use, or hepatic diseases.
The following laboratory tests may be necessary:
Serum pregnancy test, if applicable
Liver function tests
Hepatitis profile
Punch biopsy of the involved area reveals dilated capillaries in the superficial dermis.
In cases of acquired unilateral nevoid telangiectasia, observe for progression or improvement after addressing possible estrogen excess.
In congenital unilateral nevoid telangiectasia or in cases of acquired unilateral nevoid telangiectasia that do not improve, treatment is elective.
If cosmesis is desired, camouflage cosmetics or vascular laser treatment of the involved areas may be helpful.
Advise females that the telangiectasias may worsen during pregnancy or with oral contraceptive use.
Also see Ataxia-Telangiectasia and Generalized Essential Telangiectasia.
Vascular malformations may result from a somatic mutation during embryologic development giving rise to distinct cell populations in a single individual. Paradominant inheritance, in which an autosomal mutation results in loss of heterozygosity and gives rise to a mosaic patch or twin spots, may explain the rare occurrence of telangiectatic nevi in several family members.[1, 2] Whether these alterations include different concentrations of receptors for vasoactive substances or hormones remains to be determined. Telangiectasias are almost always limited to the skin, and associated gastric telangiectasias reported in one case may have been due to the underlying hepatic dysfunction.
Regarding frequency in the United States, a review of the literature by Wilkin et al described 46 reported cases[3] ; Hynes reported on100 cases.[4] However, as a benign condition, unilateral nevoid telangiectasia is likely underreported. The congenital type, though rare, is more common in males than in females. The acquired form is noted more often in females than in males.
Congenital unilateral nevoid telangiectasia may be noted in the neonatal period or soon thereafter. In the acquired form, telangiectasias often appear in puberty or in pregnancy, but they may occur at any age.
Patches of superficial, blanchable telangiectasias may be small to large and few to numerous. They are disposed predominantly in a unilateral linear distribution. (Note the image below.)
The third and fourth cervical dermatomes are the most common sites, but the thoracic dermatomes and scattered distant sites may also be involved.
In one case in a 40-year-old woman presenting after pregnancy, superficial telangiectasias were present on the right upper extremity and cervical dermatome of the right chest unilaterally. On dermoscopy, the capillaries were found to be tortuous, ectatic, and thin.[5]
Villela-Segura observed reddened, tortuous, and reticulated capillaries on dermoscopy in a 13-year-old girl with unilateral nevoid telangiectasia. The author considers this feature to be a distinctive finding in unilateral nevoid telangiectasia and a feature that distinguishes the condition from angioma serpiginosum.[6]
A highly unusual case of a 10-year-old girl with unilateral nevoid telangiectasia on the left cheek and morphea involving the oral mucosa was reported by Hirt et al. Both the telangiectasia and lesions showed improvement with prednisone and methotrexate.[7]
The pathogenesis of unilateral nevoid telangiectasia remains unknown.
The occurrence of acquired unilateral nevoid telangiectasia in certain settings characterized by elevations of estrogen suggests hormonal causes. Such settings include puberty, pregnancy, and during oral contraceptive use. The other major setting in which this has been reported to occur is in states of hepatic dysfunction. Unilateral nevoid telangiectasia has been reported in patients with chronic liver disease due to alcoholism or hepatitis C, as well as liver metastases from carcinoid tumor[8] and colon cancer.[9]
Uhlin et al documented increased levels of estrogen and progesterone receptors in involved areas compared with normal skin[10] ; however, other reports have not been able to reproduce this finding.
Because unilateral nevoid telangiectasia has been noted in cases in which no underlying hormonal or hepatic pathology has been found, other mechanisms probably play a role in the pathogenesis.
Although reported cases often involve a dermatome or a group of dermatomes, distribution following the lines of Blaschko suggests that a postzygotic somatic mutation leads to a distinct cell population in the affected site (mosaicism).
Di Altobrando et al note that melorheostosis can be associated with unilateral nevoid telangiectasia, leading the authors to speculate on a common genetic origin of the conditions.[11]
Individual case reports have described unilateral nevoid telangiectasia in association with other systemic abnormalities. Such associations include cases associated with hormonal disturbances and hepatic dysfunction. Case reports have described an association with hyperthyroidism[12, 13] and a case of unilateral nevoid telangiectasia occurring in a hepatitis B carrier without evidence of liver dysfunction.
Tanglertsampan et al reviewed the literature and found multiple case reports of unilateral nevoid telangiectasia, some of which were associated with other diseases.[13] It is not clear if these are coincidental or not. The authors proposed a new classification system, in which acquired cases may be divided into cases with an association and cases without. Associated conditions included estrogen-related (pregnancy, puberty in women), liver-related (cirrhosis, hepatitis C, hepatitis B), skin-related (possibly pyogenic granuloma), and others (including hyperthyroidism).
Kucuk et al presented the case of a healthy 26-year-old male patient diagnosed with unilateral nevoid telangiectasia, present since childhood. The authors caution that signs of hyperestrogenism must be ruled out in male patients with unilateral nevoid telangiectasia symptoms.[14]
Punch biopsy of lesional and perilesional skin for comparison may be considered. Skin biopsy is usually not necessary because the diagnosis is usually established on clinical grounds.
Other testing is not necessary. However, Kreft et al have described the results of laser-Doppler flowmetry in a patient with unilateral nevoid telangiectasia.[15] They were able to demonstrate increased perfusion in areas of unilateral nevoid telangiectasia, even in areas that were clinically unremarkable. They also found that capillary microscopy demonstrated morphologically altered capillaries.
Pulsed dye lasers with a wavelength of 585 nm and a pulse width of 450 microseconds offer a safe and effective treatment of telangiectasias. Use caution in the thinner skin in the neck area to avoid blistering and potential scarring. Cliff and Harland reported their results with the use of pulsed-dye laser in the treatment of 5 patients with unilateral nevoid telangiectasia.[16] They found that pulsed-dye laser was an effective treatment, but they noted a recurrence of lesions in all cases. Sharma and Khandpur, on the other hand, found no recurrence in their 6 Indian patients treated with the 585-nm pulsed dye laser.[17] A moderate response was achieved in all patients, and reversible pigmentary changes were the major adverse effects.
Pulsed-dye lasers with longer wavelengths and pulse widths are now available for larger vessels.
Pulsed KTP (potassium-titanyl-phosphate) 532-nm, long-pulsed alexandrite 755-nm, pulsed diode 800- to 930-nm, long-pulsed Nd:YAG 1064-nm, and filtered broad-spectrum pulsed light sources have been used for vascular lesions, with less postoperative purpura.
In a case from China, an 8-year-old male patient with a 4-year history of unilateral nevoid telangiectasia was previously treated unsuccessfully with pulsed dye laser. The patient then underwent hemoporfin-mediated photodynamic therapy with good improvement in symptoms and no recurrence during 14 months of observation.[18]