Actinic lichen planus with milia

hyperhidrosis. The diffusion properties of BoNTA in human tissues vary between different preparations, and have a significant bearing on efficacy and toxicity. This is used to advantage in cosmesis, where greater BoNTA diffusion is ideal for treatment of frontalis wrinkles. Reduced diffusion of the toxin is desirable when injecting the lateral canthus, pretarsal orbicularis and superior orbital rim, in order to minimize toxicity resulting in diplopia, ptosis and ectropion. Eccrine glands are typically located at the dermis–fat interface and in the deep reticular dermis. They are almost always surrounded by a pad of adipocytes, and are not found alone in the subcutaneous fat. We were interested to read the recent report of Ko et al. in comparing efficacy and diffusion of three formulations of BoNTA in two patients with forehead hyperhidrosis. Their choice of intramuscular (IM) rather than the more conventional intradermal or subcutaneous administration of BoNTA was surprising, as IM injection is likely to have unintended effects on facial musculature when the aim is to treat eccrine glands only. In our experience, topical glycopyrrolate (0.5–4% cream, solution or pads) is very effective in treating craniofacial hyperhidrosis. In line with local National Health Service recommendations, we reserve BoNTA largely for axillary hyperhidrosis. Goodman reported halving the dose of BoNTA with addition of the enzyme hyaluronidase in treating hyperhidrosis. We are investigating whether enhancing diffusion of BoNTA with hyaluronidase can be repeated in a larger group of patients.