Cutaneous manifestations of scrub typhus

Lydia, Mathew (2013) Cutaneous manifestations of scrub typhus. Masters thesis, Christian Medical College, Vellore.


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OBJECTIVES: To describe the skin manifestations, clinical profile and histopathology of skin lesions in patients with scrub typhus. METHODS: A cross-sectional, observational study was performed in a tertiary hospital in Vellore, an endemic area for scrub typhus. Among adult patients with a febrile illness of 5 – 28 days duration with either a positive serum scrub typhus IgM ELISA or with an eschar, 84 patients were recruited from October 2011 to October 2012.Eschar size, distribution of skin lesions, demographic details and clinical features were recorded. The eschar was biopsied for histopathological examination. Data was analysed using Chi-square test, Fisher’s exact test and Student’s t-test. RESULTS: Patients with scrub typhus from Vellore constituted 58/84 of the study patients while the remaining were from the neighbouring districts of Tamil Nadu and Andhra Pradesh. The mean age was 44.4 ±17 years. Agricultural labourers formed the major group with 51.2 % (43/84). Average duration of fever at presentation to hospital was 9.9±4.4 days. Eschars were found in 85.7 % (72/84) of the study patients, one of whom had a concomitant rash. Maximum number of eschars; 45.8% (33/72) were located over the trunk. There were more eschars found over the anterior aspect of the body ; 87.5 % (63/72). Discrete ulcers without the overlying necrotic scab were noted in 21/72 patients and were mostly over the inner aspect of thighs (7/21). There was no significant difference in gender-wise distribution of eschar. The mean eschar size was 7.1±4.5mm. Eschars less than 5mm were seen in 15/72 (20.8 %) patients. The largest eschars were over the groin and neck which was statistically significant (p<0.05).Absence of eschar did not correlate with severe scrub typhus. Regional lymphadenopathy was seen in 13.8 % (10/72) and generalized lymphadenopathy in 6% (5/84), Most patients responded to specific antibiotic therapy. However in 4/ 67 patients defervescence took more than 72 hours. Histopathological examination of the eschar revealed vasculitis in 32/43, vasculopathic reaction in 8/43 and non-specific inflammation in 3 of which had one had peri-adnexal inflammation. Of the patients with vasculitis 75 % (24/32) had lymphocytic vasculitis, 6.25% (2/32) had leukocytoclastic vasculitis in, 18.75% (6/32) had mixed vasculitis, Panniculitis was seen in 27.9% (12/43) specimens which were mostly lobular ; 58.3% (7/12), 3/12 (25%) had septal panniculitis whereas 2/12 (16.6%) had septal and lobular panniculitis. Rare features like intraneural inflammation was seen in 2/43, granulomatous inflammation including a lipogranuloma was seen in 2/43, interphase changes in 2/43 with sub-epidermal cleft in one of them were seen. CONCLUSIONS: Our study population of patients had a higher occurrence of eschar but a low frequency of rash. Eschars may not always present with a necrotic scab. Larger eschars were located over the neck and groin. Eschars were most frequently located over the trunk. Absence of eschar was not associated with risk of complications. Leucocytosis was found to be more in patients with complications. Delayed defervescence with specific antibiotic therapy of fever was noted in few patients. Lymphocytic vasculitis and panniculitis were the common histopathological findings in eschar biopsies.

Item Type: Thesis (Masters)
Uncontrolled Keywords: scrub typhus ; Cutaneous manifestations.
Subjects: MEDICAL > Dermatology Venereology and Leprosy
Depositing User: Punitha K
Date Deposited: 21 Jun 2018 14:22
Last Modified: 21 Jun 2018 15:31

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