Pityriasis rubra pilaris in association with laryngeal carcinoma.

Pityriasis rubra pilaris (PRP) is a rare group of hyperkeratotic, papulosquamous diseases that can be acquired or inherited. Cases of PRP associated with malignancy have been rarely reported. We report a case of 46-year-old man who presented with rapidly progressing PRP as a possible initial cutaneous symptom of a previously undiagnosed laryngeal carcinoma. Microlaryngoscopy was performed because of the patient's hoarseness, and this revealed leucoplakia on the left vocal cord. Histopathological examination led to the diagnosis of squamous cell carcinoma in situ. After surgical treatment, the clinical signs of PRP began to resolve, and the patient was free of skin lesions at follow-up. This case represents a rare coexistence of PRP with malignancy, and indicates that PRP can occur as paraneoplastic dermatosis associated with laryngeal cancer.

Immunopathogenesis of psoriasis: focus on natural killer T cells.

Psoriasis is a common inflammatory skin disease triggered by dysregulated immune response and characterized by hyperproliferation and altered differentiation of keratinocytes. Formation of psoriatic lesions is thought to be elicited by the complex cellular and cytokine network arising from the pathogenic interactions between keratinocytes and components of innate and acquired immune system. Natural killer T (NKT) cells are a heterogenous T-cell lineage that has been implicated in the pathogenesis of various autoimmune diseases including psoriasis. Due to the numerous functions of NKT cells that link innate and adaptive immunity, their role in psoriasis is complex and still elusive. We summarize the currently available literature data on this issue and discuss the possible role of NKT cells in the immunopathogenesis of this autoimmune disease.