Heel fissures are a commonly encountered problem in podiatric practice causing pain and discomfort for the patient. The textbook treatment of dry heel fissures is the reduction of excess hyperkeratosis and moisturisers, footwear advice and more recently the use of adhesives but a forthcoming paper in the Journal of the American Academy of Dermatology is suggesting something completely different – topical beta-blockers. A mad moment or a novel treatment? The paper discusses the case of a 36-year-old woman with painful fissures treated topically with timolol once daily, with a successful outcome [1].
Is there any science on this? Well, topical beta-blockers are no means a stranger in the dermatology clinic. They have found a place in the treatment of infantile haemangiomas, pyogenic granulomas and other skin conditions [2]. Beta-blockers are drugs which are primarily indicated in the management of hypertension, angina and arrhythmias. Going back to college, you may recall the drugs act on Beta receptors located in the cardiovascular system. There are two types: Beta 1 and Beta 2 receptors. In the skin, there are only Beta 2 receptors expressed in sebaceous glands, keratinocytes, fibroblasts and melanocytes.
Amongst the various effects of beta-blockers is enhanced wound healing in animals and randomised controlled trials in human have demonstrated more rapid healing of burns and ulcers [3]. Studies on wound healing have shown that in chronic wounds, there is Beta 2 activation which delays epidermal barrier repair whilst beta receptor blockade accelerates it. This is primarily because beta receptor activation slows the migration of keratinocytes – important for rapid skin repair [4].
So, on that basis, there is some evidence suggest a wound-healing potential. So how does that translate to us in podiatry? Firstly, this treatment, as it affects wound healing will only be effective for deeper, dermal heel fissures. Epidermal fissures are unlikely to be enhanced by this treatment - we will still be relying on emollients and wet wrapping (see earlier blog post here). Also, owing to the biomechanics and tissue stresses it is likely that other measures of treatment will still be needed such as debridement, skin re-moisturisation and addressing footwear. Finally, in the UK, timolol is available as a topical formulation as eye drops (for reducing intra-ocular pressures in glaucoma) and is a prescription-only medicine. Using it on heel fissures is an unlicensed use. The British National Formulary also states that systemic absorption can occur even when used topically so there is a list of potential drugs it may interact with (see: https://bnf.nice.org.uk/interaction/timolol.html ). So, at the moment it may have limited benefits but for those patients with difficult deep heel fissures it may be a useful adjunct but as always, more research is required to indicate this.
References
1. Pawar, M., Treatment of painful and deep fissures of the heel with topical timolol. Journal of the American Academy of Dermatology, 2020. (In press).
2. Chen, L. and T.F. Tsai, The role of β-blockers in dermatological treatment: a review. Journal of the European Academy of Dermatology and Venereology, 2018. 32(3): p. 363-371.
3. Ruitenberg, G., et al., Ulcerated infantile haemangiomas: the effect of the selective beta-blocker atenolol on wound healing. British Journal of Dermatology, 2016. 175(6): p. 1357-1360.
4. Sivamani, R.K., et al., Acute Wounding Alters the Beta2-Adrenergic Signaling and Catecholamine Synthetic Pathways in Keratinocytes. Journal of Investigative Dermatology, 2014. 134(8): p. 2258-2266.