Behc ßet's disease (BD) is a chronic, relapsing, inflammatory multisystem disease of unknown etiology. Oral ulcers, genital ulcers, cutaneous lesions, and ocular and articular involvement are the most frequent features of the disease. Mucocutaneous lesions are considered hallmarks of the disease, and often precede other manifestations.

TLRs constitute an essential family of pattern recognition molecules that, through direct recognition of conserved microbial components, initiate inflammatory responses following infection. In this role, TLR1 enables host responses to a variety of bacteria, including pathogenic species of mycobacteria. In this study, we report that I602S, a common single nucleotide polymorphism within TLR1, is associated with aberrant trafficking of the receptor to the cell surface and diminished responses of blood monocytes to bacterial agonists. When expressed in heterologous systems, the TLR1 602S variant, but not the TLR1 602I variant, exhibits the expected deficiencies in trafficking and responsiveness. Among white Europeans, the 602S allele represents the most common single nucleotide polymorphism affecting TLR function identified to date. Surprisingly, the 602S allele is associated with a decreased incidence of leprosy, suggesting that Mycobacterium leprae subverts the TLR system as a mechanism of immune evasion.

Behçet's disease is particularly prevalent in "Silk Route" populations, but it has a global distribution. The diagnosis of the disease is based on clinical criteria as there is as yet no pathognomonic test, and mucocutaneous lesions, which figure prominently in the presentation and diagnosis, may be considered the diagnostic hallmarks. Among the internationally accepted criteria, painful oral and genital ulcers, cutaneous vasculitic lesions and reactivity of the skin to needle prick or injection (the pathergy reaction) are considered hallmarks of Behçet's disease, and often precede other manifestations. Their recognition may permit earlier diagnosis and treatment, with salutary results. This paper describes the various lesions that constitute the syndrome and focuses on those that may be considered characteristic.

Mucocutaneous lesions are the hallmarks of the disease, and especially oral ulcers precede other manifestations. The increase in clinical severity score is more pronounced in patients without regular treatment and follow-up. Male sex and a younger age at onset are associated with more severe disease.

A moderately high incidence of pemphigus was found in the Mediterranean region of Turkey as compared with that encountered in other countries. The commonest clinical subtype was PV with a 9.5-fold higher incidence than pemphigus foliaceus. It is more frequent in middle-aged people and has a female predominance. Although a relatively higher dose of steroid was needed to control the PV, the disease completely remitted in a significant proportion of the patients.