Professional background

Dr Conal Perrett MB ChB PhD(Lon) FRCP(UK) is a consultant dermatologist and dermatological surgeon at UCLH.

After medical school Dr Perrett undertook medical training in London and Oxford and was awarded the membership of the Royal College of Physicians (MRCP) in 2001 and fellowship of the Royal College of Physicians (FRCP) in 2012. His subsequent specialist training in dermatology was at Barts and The London NHS Trust and The Royal Free Hospital. In 2002 he was awarded a prestigious Cancer Research UK (CR-UK) clinical research fellowship to undertake a PhD working at their London Research Institute (now relocated to the Francis Crick Institute), the Blizard Institute of Cell and Molecular Science at Barts and The London and the St John’s Institute of Dermatology.

His research investigated (1) mechanisms of skin cancer development in immunosuppressed organ transplant recipients and (2) photodynamic therapy (PDT) to treat pre-cancerous skin lesions in these patients. In 2008 he was awarded a PhD for this work by the University of London.

In 2009 he undertook post-CCST training in dermatological surgery and Mohs micrographic surgery at University Hospital Wales, Cardiff and subsequently established the Mohs micrographic surgery and skin photodynamic therapy (PDT) services at UCLH. He also runs a specialist clinic at Harefield and Royal Brompton NHS Trust, the largest specialist heart and lung centre in the UK. This is an important service as organ transplant patients have a 100-fold higher risk of skin cancer. In addition, he has a special interest in skin problems in other groups of immunosuppressed individuals including those with ‘blood cancers’ such as chronic lymphocytic leukaemia. Again, such individuals have a much higher risk of skin cancer which can also be more aggressive.

Dr Perrett is also the dermatologist to The London Sarcoma Service at UCLH, looking after patients with cutaneous sarcomas. The London Sarcoma Service ( is one of the largest sarcoma centres in Europe and attracts tertiary referrals from across the UK.

He also served as the lead clinician for skin cancer at UCLH for many years and the lead for Mohs surgery on the London Cancer Skin Pathway Board.

Dr Perrett continues to participate in research alongside his clinical duties, including supervising PhD research students. Dr Perrett has served on the examining board of the University of London for PhD, MSc and Final MB examinations. He remains an honorary senior lecturer at University College London (UCL).

Research interests

• Dermato-oncology
• Dermatological surgery including Mohs micrographic surgery
• Photodynamic therapy (PDT) and lasers
• Skin problems in solid organ transplant recipients and other immunosuppressed patients


1. Perrett CM, Evans AV, Russell-Jones R. Tea tree oil dermatitis associated with Linear IgA Disease. Clin Exp Dermatol 2003;28:167-70
2. Perrett CM, Ilchyshyn A, Berth-Jones J. Cyclosporin in childhood psoriasis. J Dermatol Treat 2003;14:107-112
3. Perrett CM, Berth-Jones J, Dharma B. Gravitational Erythema. Br J Dermatol 2003;148 (6):1267.
4. Swale VJ, Perrett CM, Denton CP, Black CM, Rustin MHA. Etanercept-induced Systemic Lupus Erythematosus. Clin Exp Dermatol. 2003 Nov;28:604-7
5. Perrett CM, McBride S. Teicoplanin Induced Drug Hypersensitivity Syndrome. BMJ 2004;328(7451):1292
6. Perrett CM, CA Harwood, CM Proby, VL Brown, JM McGregor. Topical 5% imiquimod treatment for refractory cutaneous warts in immunosuppressed individuals. J Am Acad Dermatol 2004 (part 2); 50: Number 3
7. Perrett CM, McGregor JM, Cerio R, Karran P, Harwood CA. Expression of DNA mismatch repair proteins hMLH-1 and hMSH-2 in cutaneous squamous cell carcinoma. Br J Dermatol 2004;151(Suppl 68):81-90
8. Perrett CM, Cerio R, Khorshid M, McGregor JM. Actinic prurigo associated with cutaneous B cell lymphoma. Br J Dermatol 2004;151(Supp 68):106
9. Harwood CA, Perrett CM, Proby CM, Brown VL, McGregor JM. Topical 5% imiquimod treatment for refractory cutaneous warts in immunosuppressed individuals. Br J Dermatol 2005 Jan;152(1):122-9
10. Perrett CM, Cerio R, Harwood C. Atypical fibroxanthoma in a renal transplant recipient. Histopathology 2005;47(3):326-7
11. Perrett CM, Cerio R, Khorshid M, McGregor JM. Primary cutaneous B-cell lymphoma associated with actinic prurigo. Br J Dermatol. 2005 Jul;153(1):186-9
12. O'Donovan P, Perrett CM, Zhang X, Montaner B, Xu YZ, Harwood CA, McGregor JM, Walker SL, Hanaoka F, Karran P. Azathioprine and UVA light generate mutagenic oxidative DNA damage. Science. 2005 Sep 16;309(5742):1871-4
13. Perrett CM, Tan SK, Cerio R, Goldsmith PC, McGregor JM, Proby CM, Harwood CA. Treatment of basal cell carcinoma with topical methylaminolaevulinate photodynamic therapy in an organ-transplant recipient. Clin Exp Dermatol. 2006 Jan;31(1):146-7
14. Perrett CM, J McGregor, Barlow R, P Karran, C Proby, CA Harwood. Topical photodynamic therapy with methyl aminolevulinate to treat sebaceous hyperplasia in an organ transplant recipient. Arch Dermatol. 2006 Jun;142(6):781-2
15. Perrett CM, McGregor JM, Proby CM, Karran P, Warwick J, Leigh IM, Harwood CA. Treatment of post-transplant premalignant skin disease: a randomized intrapatient comparative study of 5-fluorouracil cream and topical photodynamic therapy.Br J Dermatol. 2007 Feb;156(2):320-8
16. Zhang X, Jeffs G, Ren X, O’ Donovan P, Montaner B, Perrett CM, Karran P, Xu YZ. Novel DNA lesions generated by the interaction between thiopurines and UVA light. DNA Repair (Amst). 2007 Mar 1;6(3):344-54
17. Ekeowa – Anderson AL, Harwood CA, Perrett CM, Sahota A, Annan H, Ran H, Leigh IM, Gibbon KL. Vulval intraepithelial neoplasia and periungual Bowen's disease concordant for mucosal (HPV-34) and epidermodysplasia verruciformis (HPV-21) human papillomavirus types. Clin Exp Dermatol. 2007 May;32(3):304-7
18. Montaner B, O'Donovan P, Reelfs O, Perrett CM, Zhang X, Xu, YZ, Ren X, Macpherson P, Frith D, Karran P. Reactive oxygen-mediated damage to a human DNA replication and repair protein. EMBO Rep. 2007 Nov;8(11):1074-9
19. Perrett CM, Walker SL, O’ Donovan P, Warwick J, Harwood CA, Karran P, McGregor JM. Azathioprine treatment photosensitises human skin to ultraviolet-A radiation. Br J Dermatol 2008 Jul;159(1):198-204
20. Pozo L, Bowling J, Perrett CM, Bull R, Diaz-Cano S. Dermoscopy of trichostasis spinulosa. Arch Dermatol. 2008 Aug;144(8):1088
21. Harwood CA, Attard NR, O'Donovan P, Chambers P, Perrett CM, Proby CM, McGregor JM, Karran P. PTCH mutations in basal cell carcinomas from azathioprine-treated organ transplant recipients. Br J Cancer 2008 Oct 21;99(8):1276-84
22. Perrett CM, McGregor JM, Cerio R, Karran P, Harwood CA. Expression of DNA mismatch repair proteins and MSH2 polymorphisms in nonmelanoma skin cancers of organ transplant recipients. Br J Dermatol. 2010;162(4):732-42
23. Perrett CM, Macedo C, Francis N, Ion L, Bunker CB. Atypical Fibroxanthoma in an HIV infected individual. J Cutan Pathol 2011;38(4):357-9
24. CM Perrett. Key questions: Skin Cancer. Pulse. October 2012
25. Wilmot MC, Perrett CM, Calonje E, Weir, Bunker CB. A crusted lesion on the penis. Clin Exp Dermatol. 2014;39(2): 238-9
26. Meys R, Perrett CM. Treatment of multiple periocular eccrine hidrocystoma: is botulinum toxin or electrocautery more effective? Clin Exp Dermatol. 2015 Jan;40(1): 101- 3
27. Chandrakumar A, Veitch D, Proctor I, Hughes S, Perrett CM. Primary eccrine carcinoma treated with Mohs micrographic surgery and adjuvant radiotherapy. Clin Exp Dermatol. 2015 Mar; 40(2): 204-5
28. Cirsoid aneurysm: a clinicopathological reminder. Veitch D, Kravvas G, Perrett CM.Clin Exp Dermatol. 2015 Oct;40(7):822-3. doi: 10.1111/ced.12611. Epub 2015 Mar 1
29. A Case of Hereditary Leiomyomatosis and Renal Cell Carcinoma. Mehrtens S, Veitch D, Kulakov E, Perrett CM. Case Rep Dermatol Med. 2016;2016:3793986. doi: 10.1155/2016/3793986. Epub 2016 Apr 7. PMID: 27144040
30. A Case of Bullous Skin Disease Presenting with Odynophagia: A Diagnostic Challenge. Kravvas G, Veitch D, Perrett CM. Case Rep Dermatol Med. 2016;2016:2839104. doi: 10.1155/2016/2839104. Epub 2016 Mar 14. PMID: 2706627
31. Mohs Micrographic Surgery for the Treatment of Superficial Angiomyxomas Aberdein G, Veitch D, Perrett C. Dermatol Surg. 2016 Aug;42(8):1014-6.
32. Lymphoepithelioma-Like Carcinoma of the Skin- A Rare Tumor Treated by Slow Mohs Micrographic Surgery. Tzanidakis K, Noy ML, Calonje E, Perrett CM. Dermatol Surg. 2017 Apr;43(4):595-597.
33. Rapid ex vivo examination of Mohs specimens using optical coherence tomography. Rashed D, Shah D, Freeman A, Cook RJ, Hopper C, Perrett CM. Photodiagnosis and Photodyn Therapy. 2017 Sep;19:243-248. Doi:10.1016/j.pdt.2017.06.0006. Epub 2017 Jun 12
34. Multicentric visceral epithelioid hemangioendothelioma, with extremity dermal deposits, unusual late recurrence on the nasal bridge and TFE3 gene rearrangement. Thway K, Mentzel T, Perrett CM, Calonje E. Hum Pathol 2017Aug 27.pii:S0046-8177(17)30302-7.doi:10.1016/j.humpath.2017.08.020 (Epub ahead of print)
35. Inherited palmoplantar keratodermas: the heart of the matter. Thomas LJ, O’ Toole E, McGrath J, Freeman A, Perrett CM. Clin Exp Dermatol. 2017 Sep 22 (Epub ahead of print)
36. Metastatic Pleomorphic Dermal Sarcoma. Kravvas G, Logan I, Perrett CM. Astaric pleonais Brasileiros de Dermatologia. 2018 Mar;93(2):307-308
37. Panagou E, Ellery P, Martyn-Simmons C, Perrett C. A case of hidroacanthoma simplex in a cardiac transplant recipient. Transplantation. 2019 Sep 30. doi: 10.1097/TP.0000000000002988. [Epub ahead of print]
38. Logan IT, Zaman S, Hussein L, Perrett CM. Combination therapy of ipilimumab and Nivolumab-associated Toxic Epidermal Necrolysis (TEN) in a patient with Metastatic Melanoma: A Case Report and Literature Review. J Immunother. 2019 Oct 23. doi: 10.1097/CJI.0000000000000302. [Epub ahead of print]
39. Logan I, Kulakov E, Calnan M, Perrett CM. Sequential treatment of Superficial Basal Cell Carcinomas with topical methyl aminolevulinate photodynamic therapy and imiquimod 5% cream: a retrospective study of clinical and cosmetic outcomes. Dermatol Surg. 2020 Jan 31. doi: 10.1097/DSS.0000000000002306. [Epub ahead of print]
40. Hussein L, Perrett C. Treatment of sebaceous gland hyperplasia: a review of the literature. J Dermatolog Treat. 2020 Feb 3:1-33. doi:10.1080/09546634.2020.1720582. [Epub ahead of print]
41. Gollins CE, Shah A, Sinha K, Khan S, Paul N, Meeajun B, Abbott RA, Blasdale C, Cooper H, Harwood CA, Ismail F, Lear JT, Mackintosh L, McCormack S, Perrett CM, Proby CM, Durack A, Patalay R, Matin RN. Feasibility of a trial to evaluate nicotinamide for chemoprevention of skin cancers in organ transplant recipients in the UK. Br J Dermatol. 2020 Mar 2. doi: 10.1111/bjd.18982. [Epub ahead of print]
42. Logan IT, Shaw H, Perrett CM. Clinical management of advanced skin cancer. Dermatology in practice 2020; 26(2): 4–8

C Angwin, E Ong, I Logan, C Perrett. Myofibroblastic Sarcoma: Clinicopathological features and experience from a Sarcoma Tertiary Referral Centre. American Academy of Dermatology (AAD) Annual Meeting, San Diego March 2018

I Logan, K Vrobel, C Perrett. Pleomorphic Dermal Sarcoma: a tertiary referral center 5-year surgical experience. Br J Dermatol 2017;177(Suppl 1): 104-127

I Logan, K Vrobel, C Perrett. Pleomorphic Dermal Sarcoma: clinicopathological features and outcomes from a 5-year tertiary referral centre experience. Br J Dermatol 2017;177(Suppl 1): 128-139

Attard N, LI F, Gueranger Q, Harwood CA, McGregor JM, Perrett CM, Karran P. DNA repair and azathioprine immunosuppression. Br J Dermatol 2012; 167 (Suppl): 114-126.

Maruthappu T, Side LE, Freeman A, Perrett CM. Sebaceoma in an immunosuppressed organ transplant recipient. Br J Dermatol 2012; 167 (Suppl 1): 114-126.

Maruthappu T, Perrett CM, Kumar VKA, Side LE. Isolated sebaceous skin tumours showing immunohistochemical loss of MSH2/MSH6 gene expression may not be associated with Lunch syndrome. Br J Dermatol 2012; 167 (Suppl. 1): 100-113

Perrett CM, Cerio R, Khorshid M, McGregor JM. Actinic prurigo associated with cutaneous B cell lymphoma. Br J Dermatol 2004;151(Supp 68):106

Perrett CM, McGregor JM, Cerio R, Karran P, Harwood CA. Expression of DNA mismatch repair proteins hMLH-1 and hMSH-2 in cutaneous squamous cell carcinoma. Br J Dermatol 2004;151(Suppl 68):81-90

Perrett CM, CA Harwood, CM Proby, VL Brown, JM McGregor. Topical 5% imiquimod treatment for refractory cutaneous warts in immunosuppressed individuals. J Am Acad Dermatol 2004 (part 2); 50: Number 3

Book chapters
Perrett CM, Harwood CA, McGregor JM, Karran P. Carcinogenic mechanisms related to immunosuppressive therapy. Cancer Treat Res. 2009;146:123-32

Perrett CM, McGregor JM, Karran P, Harwood CA. Thiopurines and the sun: what should be done? Clinical Dilemmas in Inflammatory Bowel Disease. Edited by Peter Irving et al. Wiley Blackwell 2011.