Cellulitis as a postprocedural complication of topical 5-aminolevulinic acid photodynamic therapy in the treatment of actinic keratosis

BACKGROUND: Actinic keratoses (AKs) are a common premalignant tumor of the skin. Several treatment modalities exist for broad-area therapy. Photodynamic therapy (PDT) is one such treatment modality. Disruption of squamous epithelium locally compromises the normal physical barrier of the skin, potentially allowing bacteria penetration into the dermis. This may occur subsequent to PDT, resulting in cellulitis and its sequelae. Undiagnosed and untreated this can prolong recovery times and increase patient discomfort. OBJECTIVE: We report 4 cases of cellulitis that developed after treatment of AKs with PDT. These cases developed 1 to 4 days after PDT. METHODS: Standard short-contact 2-hour incubation is performed on patients receiving treatment on the face or scalp. Patients are contacted by telephone on day 1 and day 3 postprocedure. Patients are asked to call immediately if they experience no resolution of discomfort or an abrupt increase in pain in the days following treatment. Those patients reporting an increase in pain and discomfort on either of these days are asked to come to the office for examination. A culture and sensitivity is performed on those presenting with cellulitis clinically and empiric antibiotic therapy is initiated. Antibiotic therapy is adjusted, if necessary, based on the culture and sensitivity report. RESULTS: All cases of cellulitis presented with an increase in pain and burning as the primary symptom between day 1 and 4 following PDT. The appearance of impetiginized areas or pustules was clearly evident in 2 out of the 4 patients. A culture and sensitivity confirmed the growth of staphylococcus aureus in all 4 patients. CONCLUSION: Cellulitis should be considered as a possible complication in patients reporting an abrupt increase in pain or those who do not experience a gradual resolution of pain and discomfort following PDT.