Assessing and Treating Itch
Published on the 30 September 2015
Published on the 30 September 2015
Across clinical settings, pruritus (or itch) challenges care outcomes, can be hard to treat, and impacts on quality of life, mental health and mortality. The reason we itch is to protect the skin against noxious stimuli; scratching or rubbing disrupts the irritant. However, too much scratching can inflame the skin and often the cause of pruritus is not an external stimulus at all.
Accompanying many dermatologic conditions due to peripheral stimuli, pruritus also arises from systemic disease (renal, hepatic, endocrine), malignancy and medications – all of which may present as skin disorders, but actually originate in the central nervous system. Pruritus without obvious primary skin lesions should be investigated for an underlying cause.
Whatever its origins, scratching further inflames skin, stimulates nerve fibres, initiating the itch-scratch cycle. As the patient scratches, they damage the skin leading to the release of inflammatory chemicals, which increases the itchy sensation. The itch-scratch cycle alters the structure of the skin by compromising the barrier effect, which can then result in prurigo nodularis or lichenification. As such, assessing and treating itch as early as possible is an important facet of effective patient care.
When assessing pruritus, the following categories will help identify what the underlying cause might be:
Varied causes suggest multiple mechanisms may induce pruritus. Sensory nerve endings in the epidermis and dermal-epidermal junction are stimulated by chemical mediators such as histamine, opioids, serotonin and prostaglandins. Signals are transmitted along unmyelinated, histamine-sensitive and insensitive peripheral C-nerve fibres (as opposed to C-nerve fibres that transmit pain), which causes the sensation of an itch.
Pruritus characteristics will provide clues to the origin and will indicate the most effective treatment options.
Determining the underlying cause of pruritus and individualising treatment will require a nursing assessment, which should include a full history as well as a skin examination.
When performing a skin examination ensure that you use adequate lighting to inspect the skin texture and any subtle lesions that may be present. Pay attention to affected and non-affected skin, including web spaces and skin folds. Primary lesions that are unaltered by scratching may indicate a dermatological cause while secondary lesions only (eg excoriations) suggest a systemic cause. Make a note of lesion distribution and contributing conditions, such as dry skin.
When taking the patient’s history the “OLDCARTS” mnemonic formula will help to guide and order your collection of information.
Be sure to add a detailed medication history, including over the counter medications, natural remedies, new prescription medications and current medications where the dose has been altered.
The first line of management for mild, localised pruritus are topical therapies. Systemic strategies are added depending on severity and extent. These should be employed in conjunction with the removal of aggrevating external factors.
Additional measures that might be applied depending on the underlying cause:
Pruritus commonly causes physical and psychological distress. Individual evaluation with considered methodical care and management will help to aid this complex issue and provide much needed relief to your patient.
For further reading, see ‘How to Describe a Rash – A List of Terms and Corresponding Images‘
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Jan Riley is a specialist dermatology nurse based in regional New South Wales, Australia. Her postgraduate studies include a Certificate in Dermatology Nursing (USA), Master of Nursing (NP) and Certificates in Dermoscopy and Skin Cancer Medicine. Driven by a passion for “all things skin”, Jan is a staunch and passionate mentor and advocate, who is always ready and willing to share knowledge and inspire nurses to understand skin’s impact on daily lives. Her active participation in a range of professional activities has greatly assisted to raise the profile of dermatology and skin disease in the community. Jan currently develops and presents skin education modules through a co-directed nurse education company (Dermatology Nurse Education Australia) for nurses across all areas of care delivery.