A comparative analysis of mast cell quantification in five common dermatoses: lichen simplex chronicus, psoriasis, lichen planus, lupus, and insect bite/allergic contact dermatitis/nummular dermatitis.

There is a large body of literature demonstrating an important role of mast cells in adaptive and innate immunity. The distribution of mast cells in the skin varies in different parts of the body. It is well known that mast cells are important for effector functions of classic IgE-associated allergic disorders as well as in host defense against infective agents and influence the manifestation of autoimmune diseases. We aimed to quantify mast cells in five common dermatoses and compare them statistically with respect to the immunostains. We retrieved paraffin-embedded tissue sections from the archives of the Pathology Department at the UF, Jacksonville, for five cases with each of the above diagnosis from the last three years. We performed CD-117 and tolidine blue stains on each one of them. The presence or absence of mast cells was evaluated and quantified. We observed that, in the skin, mast cells are mainly located close to the vessels, smooth muscle cells, hair follicles, and nerve ending. Our study showed that the mast cell distribution pattern is different across the two methods of staining for the five aforesaid dermatoses. The other important observation was the dendritic morphology of the mast cells.