Zoster-associated neuralgias

Cannabinoid Compounds as a Pharmacotherapeutic Option for the Treatment of Non-Cancer Skin Diseases

The endocannabinoid system has been shown to be involved in various skin functions, such as melanogenesis and the maintenance of redox balance in skin cells exposed to UV radiation, as well as barrier functions, sebaceous gland activity, wound healing and the skin's immune response. In addition to the potential use of cannabinoids in the treatment and prevention of skin cancer, cannabinoid compounds and derivatives are of interest as potential systemic and topical applications for the treatment of various inflammatory, fibrotic and pruritic skin conditions. In this context, cannabinoid compounds have been successfully tested as a therapeutic option for the treatment of androgenetic alopecia, atopic and seborrhoeic dermatitis, dermatomyositis, asteatotic and atopic eczema, uraemic pruritis, scalp psoriasis, systemic sclerosis and venous leg ulcers. This review provides an insight into the current literature on cannabinoid compounds as potential medicines for the treatment of skin diseases.

Ramsay Hunt syndrome

Ramsay Hunt syndrome is defined as herpes zoster oticus associated with an acute peripheral facial nerve paresis and quite often with other cranial nerve lesions. The combination of motor, sensory and autonomic involvement leads to a variety of neurological damage patterns, i. e. facial muscle paresis, hearing and balance disorders, sensory problems and disturbances of taste as well as lacrimal and nasal secretion. Additional variability of the clinical picture of Ramsay Hunt syndrome is produced by varying patterns of skin involvement explained by individual anastomoses between cranial and cervical nerves. Knowledge of these findings and an early diagnosis of Ramsay Hunt syndrome are important as prognosis of cranial nerve damage depends on the time at which acyclovir-corticosteroid therapy is started.

Adjuvant topical therapy with a cannabinoid receptor agonist in facial postherpetic neuralgia

BACKGROUND

Postherpetic neuralgia is a frequent adverse event in herpes zoster patients and difficult to treat. Conventional analgetic therapy often fails to reduce the burning pain transmitted by unmyelinated nerve fibers. These nerves express cannabinoid receptors which exert a role in modulation of nociceptive symptoms. Therefore, topical therapy with cannabinoid receptor agonist seems likely to suppress local burning pain.

PATIENTS AND METHODS

In an open-labeled trial, 8 patients with facial postherpetic neuralgia received a cream containing the cannabinoid receptor agonist N-palmitoylethanolamine. The course of symptoms was scored with the visual analog scale.

RESULTS

5 of 8 patients (62.5 %) experienced a mean pain reduction of 87.8 %. Therapy was tolerated by all patients. No unpleasant sensations or adverse events occurred.

CONCLUSIONS

Topical cannabinoid receptor agonists are an effective and well-tolerated adjuvant therapy option in postherpetic neuralgia.

Pain: basics and relevance in dermatology

Scientific progress in pathophysiology and differentiation of pain, functional diagnostic of pain and emerging treatments highlight this subject. Basics of development of pain, as well as differentiation of nociceptive and neuropathic pain are depicted; the latter is illustrated with the example of postherpetic neuralgia. Complex regional pain syndromes are described as a third pain complex. Principles of differentiated pain management are given. Substance groups from the WHO scheme including antipyretic analgesics, non-steroidal antiinflammatory drugs (NSAIDs) and opioids are discussed. Recommendations of the Drug Commission of the German Medical Association concerning NSAIDs and of the International Association for the Study of Pain (IASP) concerning new treatment options for cancer pain are cited. Overviews amongst others from the Cochrane library for local anesthetics, opioids and for the treatment of postherpetic neuralgia are included. Tables are provided to simplify use in daily practice. The goal of this overview is a conceptual development of pain diagnosis and therapy in dermatology.