Imiquimod 5% cream: a treatment option for keratoacanthoma?

ARTICLE

Auteur(s) : Jörg Christoph PRINZ

Sir, 

With great interest we read the Letter to the Editor by K. Peris and colleagues of this issue of the European Journal of Dermatology [1]. The authors report on the successful treatment of keratoacanthoma (KA) with imiquimod 5% cream and thus confirm our recent experience that immunostimulation may be a novel treatment modality for this rapidly growing obnoxious skin tumor [2]. 

Although KA has a tendency for self-involution after several months, it represents a dilemma for the physician. In daily clinical work histopathology of lesional biopsies often does not clearly distinguish KA from squamous cell carcinoma. Final size of KA and potential tissue destruction are unpredictable. All these aspects argue for active treatment. On the other hand, KA usually occurs in heavily sun-exposed skin and is thus generally observed on the face or hands of elderly people. These sites require particular surgical skills. Surgical treatment may be impeded by relative or absolute contraindications resulting from comorbidities and systemic medication of the affected age group. This situation has lead various physicians to suggest a « wait and see » strategy without any specific treatment [3-5], putting both patient and physician at risk.

 The efficacy of imiquimod may solve this problem for at least a subgroup of patients. When a short history with rapid tumour growth strongly favours the diagnosis of KA instead of squamous cell carcinoma clinically and the patient shows restraints to other treatment modalities, the use of imiquimod 5% cream could avoid both surgery and a « wait and see » policy. In the age of evidence-based medicine, however, controlled clinical studies will have to prove efficacy in a larger number of patients to make imiquimod a standard regimen for KA [6]. n 

References

1. Peris K, Micantonio T, Fargnoli MC. Successful treatment of keratoacanthoma and actinic keratoses with imiquimod 5% cream. Eur J Dermatol 2003; 13: 413-4

2. Dendorfer M, Oppel T, Wollenberg A, Prinz JC. Topical treatment with imiquimod may induce regression of facial keratoacanthoma. Eur J Dermatol 2003; 13: 80-2.

3. Lucente FE. Giant keratoacanthoma of the nose. Otolaryngol Head Neck Surg 1985; 93: 112-6.

4. de Visscher JG, van der Wal JE, Starink TM, Tiwari RM, and van der Waal I. Giant keratoacanthoma of the lower lip: Report of a case of spontaneous regression. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996; 81: 193-6.

5. Saito M, Sasaki Y, Yamazaki N, Shimizu H. Self-involution of giant keratoacanthoma on the tip of the nose. Plast Reconstr Surg 2003; 111: 1561-2.

6. Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS. Evidence based medicine: what it is and what it isn’t. BMJ 1996; 312: 71-2.