The Journal of DermatologyVolume 46, Issue 11 p. e437-e438 Letter to the Editor Topical dapsone gel for treatment of axillary subcorneal pustular dermatosis Brent J. Doolan, Corresponding Author Brent J. Doolan brentdoolanis@gmail.com orcid.org/0000-0002-9497-0504 Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaCorrespondence: Brent J. Doolan, B.Sc., M.B.B.S., M.P.H. & T.M., Department of Dermatology, The Royal Melbourne Hospital, 300 Grattan Street, Parkville, Vic. 3050, Australia. Email: brentdoolanis@gmail.comSearch for more papers by this authorWilliam C. Cranwell, William C. Cranwell Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorJenny Nicolopoulos, Jenny Nicolopoulos Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorCon Dolianitis, Con Dolianitis Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this author Brent J. Doolan, Corresponding Author Brent J. Doolan brentdoolanis@gmail.com orcid.org/0000-0002-9497-0504 Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaCorrespondence: Brent J. Doolan, B.Sc., M.B.B.S., M.P.H. & T.M., Department of Dermatology, The Royal Melbourne Hospital, 300 Grattan Street, Parkville, Vic. 3050, Australia. Email: brentdoolanis@gmail.comSearch for more papers by this authorWilliam C. Cranwell, William C. Cranwell Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorJenny Nicolopoulos, Jenny Nicolopoulos Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorCon Dolianitis, Con Dolianitis Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this author First published: 24 June 2019 https://doi.org/10.1111/1346-8138.14953Citations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume46, Issue11November 2019Pages e437-e438 RelatedInformation

Australasian Journal of DermatologyVolume 60, Issue 3 p. e246-e248 Letter to the Editors Pseudolymphoma induced by secukinumab for treatment of chronic plaque psoriasis William C Cranwell, William C Cranwell orcid.org/0000-0001-6368-5738 Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorBrent J Doolan, Brent J Doolan Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorBarbara Radulski, Barbara Radulski Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorJenny Nicolopoulos, Jenny Nicolopoulos Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorCon Dolianitis, Con Dolianitis Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this author William C Cranwell, William C Cranwell orcid.org/0000-0001-6368-5738 Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorBrent J Doolan, Brent J Doolan Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorBarbara Radulski, Barbara Radulski Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorJenny Nicolopoulos, Jenny Nicolopoulos Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this authorCon Dolianitis, Con Dolianitis Department of Dermatology, The Royal Melbourne Hospital, Melbourne, Victoria, AustraliaSearch for more papers by this author First published: 21 February 2019 https://doi.org/10.1111/ajd.13009Citations: 4 Conflict of interest: None. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume60, Issue3August 2019Pages e246-e248 RelatedInformation

Lichen planus (LP) is a chronic mucocutaneous disease, characterised by an inflammatory immune response with sub-epithelial infiltration of T lymphocytes causing basal epithelial cell damage. Secukinumab is a monoclonal antibody that blocks IL-17A; which is the primary cytokine of Th17 cells involved in the aetiology of inflammatory skin diseases such as psoriasis. Secukinumab has been linked to induction of oral LP, but never directly to cutaneous LP. We report the first case of drug-induced cutaneous LP in the setting of secukinumab for treatment of chronic plaque psoriasis. A 56-year-old man with chronic plaque psoriasis presented with a 2-month history of violaceous and pruritic, thickened plaques on his bilateral lower limbs and buttocks in the setting of secukinumab use for psoriasis. Histological analysis showed a band-like lymphocyte inflammatory infiltrate just beneath the epithelium and was consistent with cutaneous LP. He was treated with topical betamethasone dipropionate cream with moderate effect. Initial laboratory tests including hepatitis and inflammatory screens were within normal limits. We hypothesise that this causal association may be due to a microbial trigger, activating a T-cell mediated immunologic response in CD8+ T-cells and dendritic cells, causing activation of type I interferons and an inflammatory skin response consistent with LP. Clinicians should monitor patients for mucosal and cutaneous LP when using secukinumab or other biologic modulators of IL-17 for extended periods with psoriasis.

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