Experimental evidence supports the hypothesis that oxidative stress plays a major role in the ageing process. Reactive oxygen species are generated by a multitude of endogenous and environmental challenges. Reactive oxygen species or free radicals are highly reactive molecules that can directly damage cellular structural membranes, lipids, proteins, and DNA. The body possesses endogenous defence mechanisms, such as antioxidative enzymes and non-enzymatic antioxidative molecules, protecting it from free radicals by reducing and neutralizing them. With age, the production of free radicals increases, while the endogenous defence mechanisms decrease. This imbalance leads to the progressive damage of cellular structures, presumably resulting in the ageing phenotype. Ageing of hair manifests as decrease of melanocyte function or graying, and decrease in hair production or alopecia. There is circumstantial evidence that oxidative stress may be a pivotal mechanism contributing to hair graying and hair loss. New insights into the role and prevention of oxidative stress could open new strategies for intervention and reversal of the hair graying process and age-dependent alopecia.

The desmosomes form the basis of intercellular support structure within the epidermis. However, various junctions, including gap junctions, adherens junctions, and tight junctions play an important part in the intercellular bridges that are vital for cell-cell interactions and structural stability. Numerous mutations can affect the genetic structure that make up these junctions and in turn cause disease. Most of these conditions have hair abnormalities and this article will briefly elucidate the various manifestations in the hair. As these junctional elements are found in other organs like the heart, liver, and eye, there could be serious systemic associations along with the hair changes.

India is known for its rich biodiversity, with a wide variety of wild floral and faunal species. This wildlife treasure of ours faces the threat of extinction due to rampant poaching and illegal trade. With most of the wildlife offence cases related to mammals having hair as physical evidence, it becomes imperative to use this evidence in the best possible way for wildlife crime investigation. We discuss the value of hair evidence with special reference to species characterization/identification using microscopic hair characteristics, keratin patterns, and mitochondrial DNA typing. The relevance of the techniques with respect to Indian scenario is specially taken care of and microscopic hair characteristics of one of the highly endangered species along with its keratin pattern are described. Finally, the use of mitochondrial DNA for species identification is also discussed.

Finasteride (1 mg/day) is widely utilized by dermatologists for the treatment of androgenetic alopecia. Although enjoying a relatively good safety profile, several sex-related adverse effects have been reported with this drug. Here we report two cases of gynecomastia, one of them bilateral, caused by Propecia^® prescribed for the treatment of androgenetic alopecia. Although relatively rare, physicians should be aware of this side effect and inform their patients when prescribing this medication.

Menke's syndrome and Elejalde disease are the two neurodegenerative disorders of dermatological interest. These patients present with characteristic hair changes which may be of diagnostic value in resource-poor setup where facilities for specific genetic analysis are not available. Simple light microscopic examination of hair may be a helpful diagnostic tool to pick up such cases.