Psoriasis is a common skin disorder affecting around 3% of the adult population. As part of the disorder, nail changes are frequently observed. These are most commonly in association with the skin changes, but rarely, may arise without. The severity of the nail disease often correlates to the severity of the skin disease. Clinical symptoms of nail psoriasis are diverse and include increased growth rate, onycholysis, pitting, splinter haemorrhages, sub-ungual debris, oil spots and in severe cases, nail loss. Although, they represent a relatively small surface area of the body, the condition can have a significant effect on the patient’s quality of life and daily activities.
The statistics show that nail psoriasis is not uncommon amongst patients with the skin disorder. Data suggested that around 30% of patients with have nail involvement at any one time and almost 90% of patients with psoriasis will have nail involvement at some stage in their lives [1]. However, management of psoriatic nails has proven difficult to achieve. The anatomy of the nail apparatus is not suited particularly well to topical treatment applications, and absorption is very poor. Consequently, treatments can be sometimes prolonged with little signs of improvement in the nail appearance over time.
In 2013, a Cochrane review of nail psoriasis [2] highlighted the deficiencies in its management, suggesting that topical treatments were lacking in sufficient evidence and did not appear to work. Systemic treatments commonly used for plaque psoriasis at that time such as methotrexate and ciclosporin also showed little effect. However, we have seen the gradual introduction of the class of drugs known as biologicals (or biologics) for a range of conditions including psoriasis. Biologic drugs work by changing the operation of natural intracellular and cellular actions and their effect has revolutionised the treatment of many diseases.
Many biologic drug studies have been undertaken assessing their effect on the skin in psoriasis [3], with limited data focused on the effect of the patient’s nails undergoing these modern treatments. In the Journal of the European Academy of Dermatology and Venereology (JEADV), Elewski et al., have published their results from a study which focused on the effects of adalimumab (Humira®) as a treatment for patients with nail psoriasis. The research followed patients for 52 weeks as they underwent the biologic treatment (40mg every fortnight) and demonstrated that nail improvement was continuous. It was measured using the Nail Psoriasis Severity Index [4] (also known as the NAPSI) which measures the amount of nail surface affected by the disease. In addition, the patient quality of life was also assessed.
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This work confirms what has been suggested in previous studies of biological agents used in the treatment of psoriasis, but this is the first study to focus on the nails. Although this is a very positive outcome, unfortunately, the treatment is not going to be available for all patients with nail psoriasis in the United Kingdom. Current NIHCE guidelines only permit the drug for for the treatment of severe plaque psoriasis which has failed to respond to standard systemic treatments (including ciclosporin and methotrexate) and photochemotherapy, or when standard treatments cannot be used because of intolerance or contra-indications.
References
1. Baran R, Dawber R, DeBerker D, Haneke E, Tosti A: Baran and Dawbers Diseases of the nails and their management. Oxford: Blackwell Scientific; 2001.
2. de Vries AC, Bogaards NA, Hooft L, Velema M, Pasch M, Lebwohl M, Spuls PI: Interventions for nail psoriasis. The Cochrane database of systematic reviews 2013(1):Cd007633.
3. British Association of Dermatologists: Guidelines for biologic therapy for psoriasis: methods, evidence and recommendations. In. London; 2017.
4. Rich P, Scher RK: Nail psoriasis severity index: a useful tool for evaluation of nail psoriasis. J Am Acad Dermatol 2003, 49(2):206-212.