Cutaneous findings in paediatric solid organ transplant recipients
Authors: C.C. Coughlin, D.H. Siegel
Journal: British Journal of Dermatology (2018)

Linked Article: Foo et al. Br J Dermatol 2018; 179 1368–1375. Long-term graft survival for paediatric solid organ transplant recipients (POTRs) continues to increase.1 Thus, longitudinal outcomes data for comorbidities is ever more important. In this issue of the BJD, Foo et al.2 present a 10-year follow-up of a cohort of POTRs initially reported in a study of paediatric renal and liver transplant recipients 5–16 years post-transplant.3 In their initial study, none of the 95 POTRs had developed skin cancer. In the longitudinal cohort of 45 patients reported in this issue with 15–27 years of post-transplant follow-up, all remained skin cancer free. This outcome is encouraging, as skin cancer has previously been reported as the most common cancer in paediatric renal transplant recipients and the second most common in other POTRs.4, 5 However, these results must be interpreted with caution. Firstly, as acknowledged by the authors, their study was limited by a 51% attrition rate (46 of 91 eligible patients lost to follow-up). The 45 patients in this study is a much smaller cohort than that of Penn who reported outcomes for 512 POTRs.4 Foo et al.'s difficulty in retaining their initial cohort for long-term follow-up underscores one of the challenges in tracking paediatric patients who transfer to adult providers as they age. Strategies such as obtaining consent to contact extended family members (and parents for children who turn 18 years old during a study) if participants are not reachable; standard documentation of contact information, including new provider names, when participants transition care; and consent for use of national health identification numbers to track participants in countries with these numbers could help future efforts at retention. Secondly, their population included 37 liver transplant recipients and eight renal transplant recipients. Without including cardiac and pulmonary (in addition to intestinal) transplant recipients, their data do not represent patients that might have more aggressive immunosuppressive regimens. More work needs to be done in evaluating the relationship between immunosuppressive medications (e.g. specific medications, duration, episodes of rejection) and cutaneous outcomes in this population. Despite these limitations, data from patients 15–27 years’ post-transplant is impressive follow-up. Estimates of the delay to onset of skin cancer in POTRs vary widely, often around 10–20 years,5 although the upper range of incidence can extend much further.4 A major strength of this study is the inclusion of physical exams and follow-up questionnaires. Naevus count, a marker for melanoma risk, increased over time in these POTRs (median of five naevi increased to 23 in the follow-up study). Age, sun exposure and immunosuppression could all contribute to this increase. A study by Song et al. investigating naevi in pediatric haematopoeitic stem cell transplant (HSCT) recipients, another population with significant immunosuppression exposure, noted higher naevus counts in patients post-HSCT compared with controls.6 A control group would be helpful to interpret Foo et al.'s data; their patient population would be expected to develop more naevi as they aged, and a control group could help to distinguish if they developed a different number or distribution of naevi than a nonimmunosuppressed group. That said, increasing naevi and the large range at follow-up (1–224) shows POTRs need skin surveillance over time. Similarly, their data on ultraviolet radiation (UVR) exposure and photoprotection is striking. The increase in reported sunburn episodes from 22 to 35 patients experiencing sunburns is notable. As part of the initial study, all patients received education about photoprotection. However, some of these patients may have aged out of childhood and into adolescence or young-adulthood, and thus away from close parental supervision during the follow-up period which potentially could contribute to riskier sun exposure behaviour. However, patients did not report a decline in sunscreen use. The use of artificial tanning beds by 22% of patients in the current study is alarming, and underscores the importance of continued education, counselling and frank conversations with POTRs. Dermatologists are important members of the teams caring for transplant recipients. We need to educate transplant physicians, nurses and pharmacists, in addition to patients and families, about risks from UVR exposure. In a recent survey-based study of POTRs and their guardians, 64% and 73%, respectively, of participants believed it was best to receive educational reminders at least once per year.7 Patients in the current study more commonly preferred paper handouts. One such paediatric-focused handout is available on the Society for Pediatric Dermatology website (https://pedsderm.net/for-patients-families/patient-handouts/#PediatricSkinCancer).8 Both the behaviour and stated preferences of POTRs support regular skin cancer and photoprotection education. The study by Foo et al. is helpful in its attempts to risk-stratify patients, as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are often not captured in national cancer databases,9, 10 which increases the difficulty of capturing this data on a mobile patient population. The authors argue that increased screening is needed for the subset of this population with naevus counts > 50 over 15 years post-transplant. Further work is needed to better define this subset at higher risk for melanoma, in addition to identifying patients at higher risk for BCC and SCC. This data would inform the development of guidelines to help standardize dermatological screening and follow-up recommendations. In summary, the paper by Foo et al. in this issue of the BJD advances our knowledge of cutaneous sequelae in POTRs, and highlights research directions in this area. We would like to acknowledge and thank Sonal Shah, MD for critical review this editorial. None declared.