WASHINGTON (FRONTLINE MEDICAL NEWS) Children who have had a hematopoietic stem cell transplant (HSCT) have an increased risk of benign and atypical nevi, Dr. Johanna Sheu reported at the annual meeting of the American Academy of Dermatology.

These patients need to have routine skin exams and be educated about sun protection needs, she said. Based on her study, these needs are not routinely met.

At least 1 year after undergoing HSCT at Boston Children’s Hospital, 85 posttransplant patients had significantly more nevi and more atypical nevi than did 85 healthy controls who were matched by age, gender, and Fitzpatrick skin type. In addition, 41% of the transplant recipients had at least one actinic keratosis, a basal or squamous cell carcinoma, or a solar lentigo; 11% had at least one nevus spilus.

Moreover, “sun protection … and dermatology follow-up was poor” among the transplant recipients, said Dr. Sheu, of MassGeneral Hospital for Children, Boston. About 40% of the transplant recipients reported having a sunburn since their transplant, only 15% reported daily use of sunscreen, and 53% said they did not recall being told that sunburn could trigger graft-versus-host disease (GVHD).

About one-third of the patients had never seen a dermatologist; of those who had, two-thirds had only seen the dermatologist once, Dr. Sheu reported.

Late skin effects of HSCT are not as well described in children as they are in adults, she said. In adults, late skin effects include vitiligo, psoriasis, nonmelanoma skin cancers, and an increased nevi count.

The children in the study had undergone an HSCT between 1998 and 2013, at a median age of about 7 years (range was 1 month to 19 years). At the time of their skin exams, their mean age was 14 years, and they had been followed for a median of almost 4 years. Nevi were counted on the forearms, backs, legs, palms, and soles.

The median nevi count was 44 nevi, significantly more than the level seen in control subjects. Transplant recipients also had significantly more nevi in sun-exposed areas of the body, as well as on the palms and soles. Transplant recipients were more likely to have atypical nevi and to have nevi greater than 5 mm in diameter.

In addition to fair skin, factors associated with an increase in the overall nevi count included being older than age 10 at the time of the transplant and having total body irradiation, pretransplant chemotherapy, and myeloablative conditioning. Having had a sunburn since the transplant, reported by 40%, was also a risk factor.

Chronic GVHD and chronic GVHD of the skin were associated with the presence of atypical nevi; acute GVHD, the duration of immune suppression, and the use of topical steroids or calcineurin inhibitors were not associated with increased risk of atypical nevi.

She and her coinvestigators are currently analyzing the pathogenesis of these late effects in this population, and autoimmune skin conditions – vitiligo and alopecia – in 25% of the transplant recipients in the study.

In 2013, 1,100 children under aged 16 years in the United States underwent a bone marrow transplant, she noted.

Dr. Sheu had no disclosures.