Atopic dermatitis and psoriasis are traditionally considered diseases that cannot coexist, since they are described as the result of the activation of opposing inflammatory pathways. However, this belief has been debunked, and numerous cases of psoriasis induced by dupilumab, a biologic treatment for atopic dermatitis, have been reported. We report three cases of dupilumab-induced psoriasis and we present a literature review including cases of “de novo” psoriasis and of the relapse of psoriasis that occurred during treatment with dupilumab. In total, 39 publications met the inclusion criteria, including 112 AD patients, 101 of whom developed “de novo” psoriasis, and 11 with a flare of pre-existent psoriasis. In the first group, patients more frequently developed plaque psoriasis on the scalp and extremities, after an average latency period from the initiation of dupilumab of 5 months. In the second group, the incidence of dupilumab-induced relapses of psoriasis was 43%, after an average of 4 months since the first administration. The most common psoriasis type was plaque psoriasis, with the involvement of the scalp and upper extremities. Dupilumab was interrupted in 38% of patients with “de novo” psoriasis and in 50% of relapsed patients, leading, in most cases, to an improvement of psoriasis. In conclusion, atopic dermatitis and psoriasis can definitely co-exist, and biologic drugs used to treat the former can promote the latter. It is thus crucial to perform a careful personal and familiar anamnesis before prescribing any biologic treatment. Moreover, a study of cytokine expression and blood proteomic markers could be considered in these patients.

Background: Topical ivermectin is an anti-inflammatory and anti-Demodex drug for papulopustular rosacea. Rosacea is a relapsing disease and the time between recurrences should be considered alongside efficacy Objectives: The aims of this study were to assess the time of first relapse and relapse rates of Demodex mite infestation and papulopustular rosacea Methods: We conducted a prospective study of subjects affected by different degrees of papulopustular rosacea. Patients that achieved a complete response after treatment were monitored every 4 weeks and up to 32 additional weeks. For each patient, we evaluated recording the time to first relapse and relapse rate of Demodex mite infestation and rosacea. Results: The overall success rate on Demodex infestation was 87.5%. only 12.5% relapse. Ivermectin leads to complete response in 70% of patients. Median time to relapse was 140 days, the mean time was 152 days. The global success rate was 54.76%. Conclusions: Topical ivermectin keeps a remission of Demodex infestation and clinical remission for long time. We proposed a twice-weekly ivermectin maintenance therapy to reduce recurrences.