Infantile Hemangiomas the Scalp Delaying Treatment May be Best Option

Pulse Dye Laser for Infants Under 3 Months Associated with Permanent Hair Loss

Infantile hemangiomas are benign (non-cancerous) growths of blood vessels. They are often viewed as types of birth marks. Infantile hemangiomas are the most common tumor of infants. About 1 in 20 infants have a hemangiomas so they are quite common. Girls are affected more than boys and caucasian children are most affected. Premature babies and low birth weight babies are at increased risk to develop hemangiomas.

The blood vessels in the area of the hemangioma receive signals to grow and multiple much more than they should. Most infantile hemangiomas appear at birth or within a few weeks. The grow rapidly in the first few months after birth and by month 3, most pediatricians will say that the hemangioma has reached about 80 % of the maximal size it will become. 80 % of hemangiomas stop growing by month 5. However, by age 1, the hemangioma has likley reached its maximal size and starts shrinking or “involuting.” Involution can happen over a few years (i.e. 1 to 6 years) as opposed to a few months so it is a very slow process of involution. About 50 % of children with hemangiomas are left with some sort of scar tissue or extra blood vessels at the site of the infantile hemangiomas.

There are two types of infantile hemangiomas affecting the skin. Superifical hemangiomas are often called strawberry hemangiomas and grow just under the skin. Deep hemangiomas grow deeper under the skin and take on a blue or purple appearance rather than red.

Superfical hemangiomas can be left to resolve on their own in some cases. If the hemangioma involves a sensitive area like the eye or face, Beta blockers are often used now as ‘first-line’ agents. Pulsed dye lasers can be used for superficial hemangiomas and ulcerating hemangiomas

Yang et al, 2022

A new study set out to determine if infants having PDL treatments for their infantile hemangiomas were more likely to develop permanent hair loss.

Yang et al identified 47 patients with infantile scalp hemangiomas and who had received treatment with PDL. There were 14 boys and 33 girls with a mean age of 4.5 months. For 38.3 % of infants, hair growth in the treatment area nearly returned to normal after PDL treatments. For 46.8% of infants, there were varying degrees of hair loss after PDL treatment but some amount of regrowth was still evident. For 14.9% of patients, there was no regrowth and these infants were said to have long term alopecia.

The authors looked further for predictors of permanent hair loss. Compared with the older patients receiving treatment, patients younger than 3 months who started PDL treatment had a higher risk of developing long-term hair loss (odds ratio, 30.833; 95% confidence interval, 4.079–232.025; p = 0.01). The total number of PDL sessions, post-treatment blisters, and location of IH were not shown to be significantly associated with the development of long-term alopecia.

Conclusions and Comments

Pulse dye lasers are wonderful to target blood vessel growths. The laser has a wavelength of 595 nm adn this targets hemoglobin with high specificity through selective photothermolysis, The denatured hemoglobin embolizes the blood vessels to clear the lesions. Not only does the 595-nm wavelength target hemoglobin but it can also be non-selectively absorbed by melanin. The latter effect may potentially damage hair bearing areas.

All in all, this study reminds us PDL treatments for scalp IH likely should be delayed to prevent the development of treatment-associated long-term alopecia.

The study is relevant to other vascular lesions inlcuding port wine stains. In 2015, Feldstein reported results of a survey administered to attendees at the 2014 Society for Pediatric Dermatology biannual meeting. The survey .was designed to evaluate the frequency of and factors contributing to long-term alopecia after PDL treatment of port-wine stains (PWS).

In this study, sixty-four pediatric dermatologists completed the survey, 50 of whom had experience using PDL. Of these physicians, 86% have used PDL to treat PWS of the eyebrow and 80% have treated PWS of the scalp. Over one-quarter of respondents (25.5%) using PDL on hair-bearing areas had at least 1 of their patients develop long-term alopecia after PDL treatment. The main conclusion of this study was that the occurrence of long-term alopecia at hair-bearing sites after treatment with PDL may be greater than previously thought.

REFERENCE

Yang et al. Risk factors of long-term alopecia after pulsed-dye laser treatment for infantile scalp hemangiomas: A retrospective study. J Dermatol. 2022 Apr 5.

Feltstein S et al. Can long-term alopecia occur after appropriate pulsed-dye laser therapy in hair-bearing sites? Pediatric dermatologists weigh in. Dermatol Surg. 2015 Mar;41(3):348-51.