Adverse Effects of Topical Photodynamic Therapy

A Consensus Review and Approach to Management

S.H. Ibbotson; T.H. Wong; C.A. Morton; N.J. Collier; A. Haylett; K.E. McKenna; R. Mallipeddi; H. Moseley; L.E. Rhodes; D.C. Seukeran; K.A. Ward; M.F. Mohd Mustapa; L.S. Exton


The British Journal of Dermatology. 2019;180(4):715-729. 

In This Article


Thus, while the main adverse effects of PDT are pain, which can usually be minimized through modification of treatment approaches, and the expected inflammatory phototoxic reaction, there have been rare reports of other miscellaneous adverse effects. PDT has been used to treat erosive pustular dermatosis, but there are also reports of the development of erosive pustular dermatosis of the scalp occurring within 1–3 months of PDT treatment of AK of the scalp.[171,172] The possibility that this may be triggered by the insult of PDT thus exists. Possibly via similar mechanisms, localized bullous pemphigoid developing 3–4 months following PDT has also been observed.[173,174] In the more recent study, the patient additionally developed blistering lesions at nontreatment sites,[174] and in both cases, while it is possible to speculate that the trigger may have been PDT, it is not clear cut and may have been coincidental. Likewise, a case of pemphigus vulgaris developing 1 week after a third PDT session at an adjacent site raises the possibility of an association, although, again, it may have been coincidental as the condition generalized.[175]

The antimicrobial effects of PDT are increasingly being explored, and infection following PDT is unusual and less likely than with other topical therapies.[89] Interestingly, despite a report of reactivation of herpes simplex virus (HSV) at the treatment site, 24–48 h after PDT for AK on the forehead,[176] topical ALA-PDT has also been investigated in eight patients with recurrent HSV infection (oral and genital), with encouraging preliminary data suggesting that PDT may have therapeutic and preventative effects in reduction of HSV recurrence; this warrants further study.[177] There was one report of a peripheral nerve palsy developing 1 week after a second treatment session with MAL-PDT for facial AK (forehead, cheek and jaw).[178] Other causes of facial palsy were excluded and, despite systemic corticosteroids, the patient had no clinical improvement in the facial palsy at the 16-month follow-up. While this may have been coincidental, the occurrence on the same side of treatment, just 1 week post-treatment, raises the possibility of causal association; this could be either due to a direct traumatic effect of PDT on the superficial facial nerve branches or through viral reactivation, although there was no evidence of this in this case. There were also four cases reported of cellulitis developing after treatment of AK with PDT.[179]

There was a report of five patients who developed transient memory impairment and global amnesia immediately after PDT for AK.[180] This did not appear to be associated with pain, and the neurological symptoms all resolved without sequelae within 24 h; the patients were investigated and no significant neurological or vascular disease was found. Three of the five patients had elevated blood pressure immediately post-treatment,[180] which has been documented in a separate report, including what was documented as hypertensive crisis in four patients after MAL-PDT. All had known hypertension and were on medication for this.[181] This latter observation is of interest in that blood pressure measurements are not undertaken routinely before, during or after MAL-PDT, but perhaps monitoring of hypertensive patients should be considered. Rarely, systemic flu-like symptoms may occur, with a report of intense phototoxic reactions and systemic malaise in two immunosuppressed patients following PDT and this has not previously been reported, so potentially there is a need to more actively enquire about this in patients who are severely photodamaged, possibly immunocompromised and receiving PDT to large areas.[123]