Singh Sanjay, Khandpur Sujay, Arava Sudheer, Rath Ramashankar, Ramam M, Singh Manoj, Sharma Vinod K, Kabra Sushil Kumar
Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Department of Pathology, All India Institute of Medical Sciences, New Delhi, India.
J Cutan Pathol. 2017 Dec;44(12):1038-1048. doi: 10.1111/cup.13047. Epub 2017 Oct 13.
Viral infections and drug reactions are the commonest causes of exanthems in clinical practice. Clinically, their overlapping features may pose a diagnostic challenge. Hematologic, in vitro, and drug provocation tests are either unreliable or impractical.
This was a descriptive, prospective study to assess and compare histopathological features of maculopapular viral and drug exanthem. Subjects fulfilling case definition of exanthems were included. Serum C-reactive protein (CRP) and absolute eosinophil count (AEC) were also studied.
Skin biopsy slides of 48 cases were evaluated and AEC and CRP were performed. Both median AEC and CRP were lower in viral exanthem compared with drug exanthem. On histopathological evaluation, features such as lymphocytic exocytosis, and dermal infiltrate of eosinophils, lymphocytes and histiocytes were seen in a significantly greater number of drug exanthems. Other findings such as focal spongiosis, acanthosis, keratinocyte necrosis, basal cell damage, papillary dermal edema and atypical lymphocytes in the dermis were also observed in higher though not statistically significant number of drug exanthem biopsies.
Certain histopathological features can help to differentiate between the two exanthems and this modality may be used in situations when there is clinical overlap and when drug rechallenge cannot be undertaken.
病毒感染和药物反应是临床实践中皮疹最常见的病因。临床上，它们的重叠特征可能带来诊断挑战。血液学、体外及药物激发试验要么不可靠，要么不实用。
这是一项描述性前瞻性研究，旨在评估和比较斑丘疹性病毒疹和药物疹的组织病理学特征。纳入符合皮疹病例定义的受试者。还对血清C反应蛋白（CRP）和绝对嗜酸性粒细胞计数（AEC）进行了研究。
对48例患者的皮肤活检切片进行了评估，并检测了AEC和CRP。与药物疹相比，病毒疹的AEC和CRP中位数均较低。组织病理学评估显示，药物疹中淋巴细胞外渗、真皮中嗜酸性粒细胞、淋巴细胞和组织细胞浸润等特征更为常见。在药物疹活检中，虽然差异无统计学意义，但局灶性海绵形成、棘层肥厚、角质形成细胞坏死、基底细胞损伤、乳头真皮水肿和真皮中非典型淋巴细胞等其他表现也较多见。
某些组织病理学特征有助于区分这两种皮疹，在存在临床重叠且无法进行药物再激发试验的情况下，这种方法可能会被采用。
