Histopathological studies on sun-exposed hexachlorobenzene-induced porphyric rat skin.

Hexachlorobenzene (HCB) is a porphyrogenic agent. The inducement of skin changes was attempted through repeated exposure of the skin of HCB-induced porphyric rats to sunlight. The following skin changes were produced in the porphyric rats; erythema, erosion, crust, skin thickening and scarring. Histopathological examination revealed the presence of acanthosis, vacuolization of the malpighian cells, subepidermal vesicle, fibrosis, dilatation and increase of the blood vessels and perivascular cell infiltration composed of lymphocytes, histiocytes and mast cells. The PAS stainability of blood vessel walls was slightly intensified. The assumption is that photosensitive flares were elicited within the short 2-month period though destruction of endothelial cells was not prominent. There were no distinct skin changes, clinically or histopathologically, in any of the three control groups.