A Comparative Histopathologic Study Between Acne Vulgaris And Steroid Induced Acne

Abstract

Acne vulgaris is a chronic inflammatory disease. It is described as a disease of excess sebum production, formation of comedone, papules and pustules, less frequently, nodules, deep pustules, or pseudocysts and in some cases, is accompanied by scarring Acneiform eruptions account for about 1% of all drug-induced skin eruptions. Steroid acne is the most frequent form of drug induced acneiform eruption that appears as a side effect of corticosteroid therapy. It might happen after topical or systemic corticosteroid administration and even after inhalation of steroids. The objective of this thesis was to highlight the difference between acne vulgaris and steroid acne both histologically and by immunohistochemistry to further unravel the difference in the pathogenesis of these two distinct closely related entities. All the study cases were subjected to full history taking and full clinical examination. This was followed by digital photography of the lesions and skin biopsy. Skin biopsy was taken from 1-2mm inflammatory papules from all cases. The present study included 12 cases that were presented with acne lesions. Cases were categorized according to the clinical diagnosis into two groups. Group 1: included 6 cases with acne vulgaris.Group 2: included 6 cases with steroid induced acneiform eruption after a history of corticosteroid consumption either topical or systemic or both. Regarding the type of lesions reported in the current thesis, group 1 presented with acne lesions in the form of comedones, papules, pustules and nodules.On the other hand, group 2 cases presented with papules and pustules with neither comedonal nor nodular lesions. Regarding the histologic findings in the current thesis, the histopathology of acne vulgaris papules showed thickened hair follicle, some follicles were destructed. A follicular plug or closed comedone composed of loosely arranged keratinized cells and sebum was seen in some hair follicles. Perifollicular inflammatory infiltrate was evident in all cases that ranged from moderate to severe. The inflammatory infiltrate was composed of PNL and mononuclear lymphohistiocytic infiltrate. Alternatively, papules from steroid acne showed infundibular dilatation with compact hyperkeratosis that resulted in microcomedo formation in 50% of cases with moderate perifollicular inflammatory infiltrate. Destructed follicles were seen in 50% of cases with mild to moderate inflammatory infiltrate. The inflammatory infiltrate was composed predominantly of PNL, and mononuclear lymphohistiocytic infiltrate.