Update on etiopathogenesis and treatment of Acne.

Acne, the most common skin disease, is a disorder of pilosebaceous units that affects adolescents mainly and adults occasionally. The pathogenesis is multifactorial. Besides genetic predisposition, other major factors include the action of androgens, pro-inflammatory lipids acting as ligands of peroxisome proliferator-activated receptors in the sebocytes, toll-like receptor-2 acting on keratinocytes, recognition of pathogen-associated molecular patterns, cytokines, chemokines, inflammasomes, neuroendocrine regulatory mechanisms, diet and other pro-inflammatory targets implicated in the activation of immune detection and response. Most of these factors converge on mammalian target of rapamycin complex1 (mTORC1) activation which is further enhanced by the nutrient signaling of Western diet. This multitude of pathogenic factors has led to a new armamentarium of drugs for the treatment of acne. Topical anti-androgens, insulin-like growth factor-1 inhibitors, peroxisome proliferator-activated receptor-modulators, acetylcholine inhibitors, topical retinoic acid metabolism-blocking agents, vitamin D analogues, antimicrobial peptides, interleukin-1α and interleukin-1ß blockers and immunotherapy are some of the novel treatment options.

Histology of indeterminate leprosy.

Skin biopsies from 20 patients with indeterminate leprosy were studied histopathologically. The most common clinical manifestation of the disease was a hypopigmented macule. In most cases, 5% to 10% of the dermis was occupied by the infiltrate. Sweat glands were involved in two thirds of the cases, and approximately half the biopsies showed involvement of arrector pili muscle and pilosebaceous glands. Ninety-five percent of the cases had involvement of the dermal nerves, with perineural infiltration being the most common finding. Twenty-five percent of the cases showed lesions of the epithelium.