P224 : Clinical and histopathologic characteristics of postinflammatory hyper- and hypopigmentation = P224 : Clinical and histopathologic characteristics of postinflammatory hyper- and hypopigmentation

다국어 초록 (Multilingual Abstract)

Background: Inflammatory skin disease can cause clinical hypopigmentation, hyperpigmentation, or both. There have been only few studies of clinical and histopathologic characteristics of postinflammatory pigmentary alteration. Objectives: To investigate the clinical and histopathologic characteristics of postinflammatory hyper- (PIHyper) and hypopigmentation (PIHypo). Methods: A clinical survey was carried out with 16 patients diagnosed with PIHyper and 9 patients with PIHypo. Punch biopsies from lesional and perilesional normal skin were performed. The sections were stained with hematoxylin-eosin, Fontana-Masson. Immunohistochemistry for melanocytes was performed. Results: No predisposition of age and sex was found in the incidence of PIHyper and PIHypo. Among PIHyper patients, contact dermatitis (25.0%) was the most common previous inflammatory skin disease, while laser treatment (33.3%) was that of PIHypo patients. Histologically, hyperkratosis, acanthosis, vacuolar alteration, dermal inflammation, as well as pigmentary incontinence were observed variably in the PIHyper lesion. Hyperpigmentation was seen in suprabasal, basal, or dermal layer. However, significant change in the number of melanocytes was not observed in the majority of PIHyper lesions. In the most cases of the PIHypo, the melanocytes did not showed change in the number of melanocytes as well. Conclusion: Both clinical and histologic features should be considered together to make a diagnosis of PIHyper or PIHypo.