Histological studies in primary neuritic leprosy: changes in the apparently normal skin

The visually normal skin of 196 patients diagnosed clinically to have prima ry neuritic leprosy was studied histologically to determine whether there w ere any specific changes due to the disease in this site. Histological chan ges due to leprosy were seen in 32.1% of the patients, and included, indete rminate leprosy in 19.4%, borderline tuberculoid leprosy in 6.6% and border line lepromatous leprosy in 6.1%. The remaining biopsies showed mild non-sp ecific dermal inflammation, mild nerve changes or no significant lesion. Th e nerve inflammation and/or granulomas were mostly in the deep dermal nerve s or neurovascular complexes. This study shows that there is a cutaneous co mponent to primary neuritic leprosy and the disease is not totally confined to nerves. The absence of visible hypopigmented patches in these patients is probably related to the deep location of the dermal inflammation.