Prurigo nodularis

TRPVl results in premature hair follicle regression and apoptosis [153]. This finding confers a therapeutic potential for TRPVl antagonists in the treatment of alopecia. In prurigo nodularis, enhanced TRPVl expression was found that normalized during capsaicin treatment [154]. 

The incidence of peripheral neuropathy, with sjmmetrical painful paresthesia of the hands and feet often accompanied by sensory loss in the legs, seems to vary with the condition that is being treated, and ranges from under 1% in patients with leprosy to over 70% in patients with prurigo nodularis (41,52). The symptoms do not correlate with either the duration of treatment or the dose. Women and elderly people seem to have an increased risk of neuropathy (53). 

Redness of the palms was observed in four of 13 patients treated with thalidomide (43). Erythroderma and peripheral eosinophilia occurred in two patients with chronic renal insufficiency who were taking thalidomide for prurigo nodularis (78). 

Goeksel, T, Xie, W, Ritzerfeld, M., Heidenreich, S., Mann, H. Prurigo nodularis and dialyzer membrane. Blood Purif. 35(Suppl 2), 26-27 (2013)... 

In a series of other dermatoses oral retinoids have been applied with varying clinical efficacy. Etretinate/acitretin were found effective in (i) lichen planus [50] including oral manifestations of lichen mucosae oris with papillomatous and erosive/bullous lesions, (ii) cutaneous variants of lupus erythematosus [11], particularly the hyperkeratotic lesions of chronic-discoid lupus erythematosus, and (iii) lichen sclerosus et atrophicans [7]. Both lichen planus and lichen mucosae oris were also shown to respond to low-dose oral tretinoin. Complete remission was observed in 13/18 patients [65]. The beneficial effect of retinoids in these entities underlines their immunomodulatory dermal action. Prurigo nodularis may be another entity responding well to systemic retinoid therapy. 

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