Reply to: "Photodistributed toxic epidermal necrolysis in association with lamotrigine and tanning bed exposure".

To the Editor: We read with great interest the article by Russomanno et al and report a similar case in a pediatric patient to expand the literature.

A burning and pruritic eruption on the shoulders and back associated with mouth sores developed in a 16-year-old adolescent girl. These developed 2 weeks after the initiation of lamotrigine and significant sun exposure. A physical examination demonstrated dusky pink macules and papules coalescing into patches and plaques, some with a targetoid appearance, on the face, trunk, and extremities. The eruption was sharply demarcated and photodistributed, sparing the bathing suit area; she had gold crusting on the vermilion lip border without other oral mucosa involvement (Figs 1 to 3). She had no genitourinary or ocular symptoms. Histopathology demonstrated interface dermatitis with foci of near-confluent epidermal necrosis (Fig 4), supportive of Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Her eruption subsided significantly 1 week after the initiation of a 10-day prednisone taper.

Figs 1 to 3

1) Bright pink to slightly dusky papules and plaques in a striking photodistributed pattern on the chest, 2) sparing of the nasolabial folds with crusting on the upper vermillion lip, 3) sharp sparing of the bathing suit area on the back.

Fig 4

There was interface dermatitis with foci of full thickness epidermal necrosis and a superficial perivascular lymphocytic infiltrate. (Hematoxylin-eosin stain; original magnification: ×10.)

Because of the striking nasolabial sparing, an antinuclear antibody test was performed, and its level was only mildly elevated (1:80). Epstein-Barr virus panel revealed only the elevated level of IgG. Findings were negative for anti–double-stranded DNA, antihistone, and Mycoplasma pneumoniae antibodies. The complete blood cell count with differential count and comprehensive metabolic panel were within the normal range at presentation and 1-week follow-up.

We report this case to include a pediatric patient with the unusual presentation of photodistributed SJS/TEN associated with lamotrigine, similar to the case of an adult recently described. Although human immunodeficiency virus infection, malignancy, and genetic factors (including certain human leukocyte antigen haplotypes and polymorphism) are well-established risk factors for the development of SJS/TEN, physical stimuli and Koebner phenomenon are less well-known risk factors. We concur with the theories postulated by Russomanno et al with regard to the mechanism of action. Further research to clarify the relationship between ultraviolet radiation and high-risk medications for SJS/TEN is needed, as counseling on stricter sun-protective measures may be necessary, although this is challenging because of the rarity of the diagnosis. Clinicians should consider SJS/TEN in the differential diagnosis of photodistributed eruptions, especially in the setting of lamotrigine use.

Conflicts of interest

None disclosed.