Photodynamic Therapy (PDT) is a non-invasive treatment successfully used for neoplastic, inflammatory and infectious skin diseases. One of its strengths is represented by the high safety profile, even in elderly and/or immuno-depressed subjects. PDT, however, may induce early and late onset side effects. Erythema, pain, burns, edema, itching, desquamation, and pustular formation, often in association with each other, are frequently observed in course of exposure to the light source and in the hours/days immediately after the therapy. In particular, pain is a clinically relevant short-term complication that also reduces long-term patient satisfaction. Rare complications are urticaria, contact dermatitis at the site of application of the photosensitizer, and erosive pustular dermatosis. Debated is the relationship between PDT and carcinogenesis: the eruptive appearance of squamous cell carcinoma (SCC) in previously treated areas has been correlated to a condition of local and/or systemic immunosuppression or to the selection of PDT-resistant SCC. Here we review the literature, with particular emphasis to the pathogenic hypotheses underlying these observations.

Relapsing polychondritis is an immune-mediated systemic disease characterized by recurrent episodes of inflammation of cartilaginous and proteoglycan-rich tissues, resulting in progressive anatomical deformation and functional impairment of the involved structures. Auricular and nasal chondritis and/or polyarthritis represent the most common clinical features, but potentially all types of cartilage may be involved. Because of the pleomorphic nature of the disease, with non-specific symptoms at the onset, the diagnosis of relapsing polychondritis is often delayed. In this review article we provide a comprehensive look into clinical presentation, laboratory and instrumental investigations, diagnostic criteria, and therapeutic options.

The rosemary plant, Rosmarinus officinalis L., one of the main members of the Lamiaceae family, is currently one of the most promising herbal medicines due to its pharmaceutical properties. This research aimed to evaluate the antioxidant role of Rosmarinus officinalis and its bioactive compounds on the skin, with a focus on the newly emerging molecular mechanisms involved, providing extensive scientific evidence of its anti-inflammatory, antimicrobial, wound-healing and anticancer activity in dermatological practice. The search was conducted on articles concerning in vitro and in vivo studies in both animals and humans. The results obtained confirm the antioxidant role of R. officinalis. This assumption derives the possibility of using R. officinalis or its bioactive elements for the treatment of inflammatory and infectious skin pathologies. However, although the use of rosemary in the treatment of skin diseases represents a fascinating line of research, future perspectives still require large and controlled clinical trials in order to definitively elucidate the real impact of this plant and its components in clinical practice.

Lipid peroxidation (LPO) is a biochemical process through which lipids are subjected to a peroxidation reaction in the presence of free radicals. The process can cause alterations in biological membranes and the formation of substances harmful to the body that can form aggregates with proteins and nucleic acids. Malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) are the main products of LPO. These compounds have cytotoxic and genotoxic properties and contribute to the pathogenesis of various diseases. This research focuses on the correlation between LPO and skin diseases. For some skin diseases, such as psoriasis, vitiligo, and alopecia, LPO products have been shown to have a clear role in the pathogenesis of the disease. Lipid aldehydic products like MDA and 4-HNE can enhance inflammation by stimulating pro-inflammatory genes and producing cytokines. Furthermore, these products can stimulate cell death and increase oxidative stress. For other diseases (atopic dermatitis, urticaria, pemphigus, and melanoma), the role of LPO is unclear, even if the levels of LPO biomarkers are elevated in proportion to the severity of the disease. LPO can also be exploited to counteract the proliferation of neoplastic cells. Therefore, enhancing LPO would play an adjuvant role in the therapy of neoplastic diseases such as melanoma. In particular, the therapeutic implication resulting from the role of LPO products in the cytotoxicity induced by photodynamic therapy used for the adjuvant treatment of melanoma could be of interest in the future.

Atopic dermatitis is a chronic inflammatory skin disease in which the overproduction of reactive oxygen species plays a pivotal role in the pathogenesis and persistence of inflammatory lesions. Phototherapy represents one of the most used therapeutic options, with benefits in the clinical picture. Studies have demonstrated the immunomodulatory effect of phototherapy and its role in reducing molecule hallmarks of oxidative stress. In this review, we report the data present in literature dealing with the main signaling molecular pathways involved in oxidative stress after phototherapy to target atopic dermatitis-affected cells. Since oxidative stress plays a pivotal role in the pathogenesis of atopic dermatitis and its flare-up, new research lines could be opened to study new drugs that act on this mechanism, perhaps in concert with phototherapy.