Thiotepa-induced cutaneous toxicity in pediatric patients: Case report and implementation of preventive care guidelines

Abstract

Thiotepa, a highly lipophilic, alkylating agent, and/or its active metabolites may be excreted in part via skin in patients receiving high-dose therapy. We present a case of cutaneous toxicity observed in a 4.5-year-old girl patient with medulloblastoma treated with a high-dose thiotepa conditioning regimen before autologous stem cell transplantation. Skin lesions, as well as their pattern and locations, were evocative of thiotepa toxidermia. After the case herein described, preventive care guidelines were implemented in our unit as from 2014. A retrospective follow-up of 26 pediatric patients receiving thiotepa prior to stem cell transplantation was performed until March 2018. In this series of patients, only one patient experienced cutaneous toxicity as reported herein. Thereafter, only mild cutaneous toxicity was observed, even with double or triple transplantation protocols with high-dose thiotepa. Clear preventive care instructions should be detailed in the Summary of Product Characteristics in order to minimize the cutaneous toxicity of thiotepa.

Keywords : Thiotepa, cutaneous toxicity, case report, guidelines, children

Introduction

Thiotepa is an alkylating agent, chemically and pharmacologically related to nitrogen mustard.1 It is often given as part of conditioning regimens in combin- ation with carboplatin, fludarabine, treosulfan, as well as with other high-dose chemotherapeutics (Table 1). There are several dosing recommendations based on the indication.1

Thiotepa is a highly lipophilic compound, undergo- mercapturate.2 Thiotepa was also detected in skin and sweat of patients receiving high-dose regimens.Adverse reactions in the System Organ Class skin and subcutaneous tissue disorders, reported in pediatric patients and listed as very common (frequency 1/10), are rash, erythema, desquamation, and pigmentation disorders.1 Severe toxic skin reactions including cases of Stevens–Johnson syndrome and toxic epidermal reported half-life of the parent drug varies from 1.4 to 3.7 h and that of its major metabolite tepa from
4.9 to 17.6 h,2 so it is expected that most of both thio- tepa and tepa will be cleared from the body within 48 h. Identified metabolites (tepa, monochlorotepa, and thio- tepa-mercapturate) are excreted in the urine with 0.5% mean urinary recovery for thiotepa (unchanged drug) and monochlorotepa and 11% for tepa and thiotepanecrolysis are listed with frequency not known (cannot be estimated from the available data).

We present a case of skin toxicity observed in a pediatric patient treated with a high-dose thiotepa con- ditioning regimen before autologous stem cell transplant- ation (autologous SCT). Based on the identified adverse reaction, a practice guideline was introduced in our unit in order to prevent cutaneous toxicity of thiotepa.

Case report

A 4.5-year-old girl patient with medulloblastoma was hospitalized for an autologous hematopoietic stem cell transplantation (autologous HSCT) at the Queen Fabiola Children’s University Hospital (QFCUH), Brussels, Belgium, from 28 October until 29 November 2013. Upon admission, the patient was in good general condition, weighing 16 kg, with body surface area of 0.68 m2. Liver and kidney function tests were normal. The conditioning regimen was carboplatin–thio-tepa–etoposide based: carboplatin (500 mg/m2/day) on day 8, 7, and 6, i.e. 340 mg/day, thiotepa (300 mg/ m2/day), i.e. 205 mg/day, and etoposide (250 mg/m2/ day), i.e. 170 mg/day, on day 5, 4, and 3 followed by autologous HSCT on day 0, 8 November 2013. Thiotepa (Tepadina®, Adienne, Caponago, Italy) was administered as a single daily intravenous infusion via a central venous catheter for three consecutive days.

As of day 3, the patient developed thoracic hyper- pigmentation in the catheter dressing areas (Figure 1). The following days, an extension (Figure 2) of the cuta- neous lesions was noted, and a pruritic rash affecting the axillary and inguinal (Figure 3) folds, thorax, and upper neck was noticed. Erythematous zones merged into large maculopapular copper-colored plaques, with localized cutaneous detachment when central catheter dressing
was removed. These lesions, as well as their pattern and locations, were evocative of thiotepa toxidermia.The thiotepa-induced erythroderma resolved after topical corticosteroids (betamethasone, Diprosone® ointment, MSD) applied from 12 November until 20 November.As from 20 November, desquamation was noticed in the erythroderma areas that started to fade.

A Naranjo4 algorithm for causality assessment of an adverse drug reaction (ADR) was performed, revealing a total score of 8 suggesting that the cutaneous toxicity was probably (total score of 5 to 8: probable ADR) due to the use of thiotepa.Written informed consent for patient information and images were provided by the patient’s legally authorized representatives.

Discussion

Skin toxicity related to the use of thiotepa is a well- known adverse reaction. Horn et al.3 described hyperpigmentation in occluded skin areas in five female adult patients after receiving high-dose thiotepa. Hyperpigmentation was attributed to thiotepa excreted onto the skin by sweat with accu- mulation beneath occluding adhesive materials.

In order to characterize the cutaneous reactions to thiotepa in children, Rosman et al.5 published a review of 38 pediatric patients receiving high-dose thiotepa prior to autologous SCT. Nearly 80% of the patients showed a consistent pattern of diffuse erythema pro- gressing to hyperpigmentation and desquamation. Affected primary locations were intertriginous and occluded areas as well as the trunk.

A case report published by Wise et al.6 described cutaneous toxicity in an adult patient receiving thiotepa and etoposide prior to autologous SCT. Although it is stated that both thiotepa and etoposide have been reported to cause hyperpigmentation in occluded areas, the authors noticed that the pattern of erythema, desquamation, and hyperpigmentation, seen in their patient, was most consistent with the cutaneous effects of thiotepa reported earlier in pediatric patients.5 A Product Monograph,2 approved under Health Canada’s Notice of Compliance with conditions policy, on Tepadina® used to treat adult patients with central ner- vous system lymphoma, states that Tepadina® is excreted through the skin and that skin toxicity reported with Tepadina® use includes rash (predominantly involving axillae, groin, and elbows), pruritus, urticaria, erythroder- mic psoriasis, alopecia,pigmentation disorders, Stevens– Johnson syndrome (including fatal cases), and toxic epidermal necrolysis. When pharmacokinetics, more spe- cifically excretion, is discussed, it is quoted that thiotepa was also detected in skin and sweat of patients receiving high-dose regimens, although the percentage of skin excre- tion in the total dose of administration was unknown. It is also clearly stated that patients will be instructed by their health care professionals to bathe often and to avoid touching others while receiving Tepadina® as the drug can come through the skin when sweating.

Prescribing Information7,8 on Tepadina®, including its use in pediatric patients with class 3 beta-thalassemia prior to HSCT, discusses, in section 5.3, the cutaneous toxicity of thiotepa. It is stated that Tepadina® and/or its active metabolites may be excreted in part via skin in patients receiving high- dose therapy and that treatment with Tepadina® may cause skin discoloration, pruritus, blistering, desquam- ation, and peeling that may be more severe in the groin, axillae, skin folds, in the neck area, and under dressings. Patients are instructed to shower or bathe with water at least twice daily through 48 h after admin- istration of Tepadina®. Occlusive dressing has to be changed and covered skin cleaned at least twice daily through 48 h after administration of Tepadina®. Bed sheets have to be changed daily during treatment.

So far, the European Summary of Product Characteristics1 (SPC) does not provide instructions for the prevention of the cutaneous toxicity of thiotepa. After the case herein described, the following pre- ventive care guidelines were introduced at QFCUH as from 2014 :

– Give the child a bath three to four times a day: the first bath 3 to 4 h after the first thiotepa administra- tion, the last bath 36 h after the last thiotepa administration.
– Wash with water only.
– When washing the child, pay special attention to the skin fold areas such as the groin, underarm, and knee fold.
– Wash all body parts and dry off carefully with a soft towel. Avoid rubbing as this could damage the skin but gently pat dry.
– Do not apply antiperspirants or deodorants.
– Do not use moisturizers (creams, lotions, ointments, oils, etc.) while receiving thiotepa and for 36 h after the last thiotepa administration.
– If the patient is in diapers, change as soon as you notice it is wet or soiled.
– Do not use baby wipes.
– Minimize the use of tapes, avoid (large) occlusive dressings, and do a central line dressing change after each bath in order to prevent sweat accumula- tion while receiving thiotepa until 36 h post- administration.
– Change linens and clothes after each bath.
– Avoid tight clothes.

A retrospective follow-up of this practice guideline was performed. Between July 2013 and March 2018, 26 pediatric patients (Table 1) received thiotepa (Tepadina®) as part of a conditioning regimen prior to HSCT. In this series of patients, only one patient (no. 3) experienced cutaneous toxicity as reported herein. The preventive care guidelines described earlier were implemented as from patient no. 4.The Ethics Committee of QFCUH provided approval for this retrospective study (approval number 68/18).

Conclusion

Through these preventive guidelines, only mild cutane- ous toxicity was observed after patient no. 3, even with double or triple HSCT protocols with high-dose thio- tepa that were introduced as from 2015. Clear prevent- ive care instructions should be specified in the SPC in order to minimize the cutaneous toxicity of thiotepa.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

References

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