SUBMITTED 10 JUN 21 1 REVISION REQ. 16 AUG 21; REVISION RECD. 16 SEP 21 2 ACCEPTED 21 OCT 21 3 ONLINE-FIRST: JAN 2022 4 DOI: https://doi.org/10.18295/squmj.1.2022.011 5 6 Leukocytoclastic Vasculitis 7 A peculiar presentation of Scrub typhus 8 Anila Vasireddy, 1 Kanthilatha Pai, 2 Varsha M. Shetty, 3 Raviraja V. Acharya, 4 9 Ramamoorthi K., 4 Akhila Doddamani, 5 *Sharath Madhyastha P. 4 10 11 Departments of 2 Pathology, 3 Dermatology, 4 Medicine and 5 Community Medicine, 1 Kasturba 12 Medical College, Manipal Academy of Higher Education, Manipal, India 13 *Corresponding Author’s e-mail: dr.sharathymc@gmail.com 14 15 Abstract 16 Scrub typhus is a disease endemic to the Indian subcontinent caused by the obligate intracellular 17 pleomorphic organism, Orientia tsutsugamushi. Scrub typhus among other acute febrile illnesses 18 present with prodromal symptoms of fever, malaise, myalgia, anorexia followed by a distinct 19 maculopapular rash, hepatosplenomegaly, and lymphadenopathy. In this case report, we present 20 a patient who developed a rare cutaneous vasculitis secondary to infection with Orientia 21 tsutsugamushi. After performing the Weil Felix test, a diagnostic titer of 1:640 against OX-K 22 was obtained. Furthermore, a skin biopsy was carried out which confirmed the diagnosis of 23 leukocytoclastic vasculitis. The patient was treated with Doxycycline and showed a drastic 24 improvement in his symptoms. 25 Keywords: Scrub Typhus, Rickettsia; Vasculitis; Doxycycline. 26 27 Introduction 28 Scrub typhus is a disease endemic to the Indian subcontinent caused by the obligate intracellular 29 pleomorphic organism, Orientia tsutsugamushi. This organism is transmitted naturally through 30 mailto:dr.sharathymc@gmail.com the Leptotrombidium mite population and is accidentally acquired in humans via the bite of a 31 mite as a dead-end host. Scrub typhus among other acute febrile illnesses present with prodromal 32 symptoms of fever, malaise, myalgia, anorexia followed by a distinct maculopapular rash, 33 hepatosplenomegaly, and lymphadenopathy. Rarely, it can even progress to septic shock/multi-34 organ failure. As in every disease, scrub typhus can have some peculiar manifestations. There 35 have been previous case studies reporting features of hemophagocytic syndrome, 1 epididymo-36 orchitis, 2 acute severe monoarthritis, 3 and Guillain Barre syndrome. 4 In this case report, we 37 present a patient who developed a rare cutaneous vasculitis in setting of Orientia tsutsugamushi 38 infection with good response to doxycycline. 39 40 Case Report 41 A 28-year-old man farmer presented with high grade, intermittent fever (102°F), vomiting and 42 generalized muscle pain to a local primary center and was treated with antipyretics. Four days 43 later, the patient developed multiple palpable purpuric eruptions predominantly affecting the 44 lower limbs. Thereafter, the patient was subsequently transferred to our tertiary care hospital in 45 2021. 46 47 On examination, the patient’s vital signs were stable and he was afebrile when he presented to 48 our hospital. Skin examination revealed multiple palpable purpuric eruptions arranged in a 49 retiform pattern with a dusky necrotic center and peripheral rim of erythema distributed 50 symmetrically over bilateral lower limbs [Figure 1A-1C]. The mucosa, palms and soles were 51 spared. The rest of the systemic examination was deemed to be normal. 52 A panel of laboratory investigations were carried out to determine the etiology [Table 1]. A 53 routine urinalysis was unremarkable, confirming no renal involvement. Antinuclear antibody 54 (ANA) and antineutrophil cytoplasmic antibodies (ANCA), serum C3 and C4 complement levels 55 were negative, making vasculitis due to autoimmune inflammatory disorders less likely. 56 57 This constellation of findings is unique to acute febrile illnesses. Therefore, a panel of serum 58 studies were performed to determine the organism. Subsequently, leptospirosis, dengue (NS1 Ag 59 & anti-dengue IgM), malaria, and Hepatitis B & C were ruled out. 60 61 However, a Weil Felix test (WFT: tube agglutination) was performed and a diagnostic titer of > 62 1:640 against OX-K was obtained. The skin biopsy done from the lesion revealed necrotizing 63 vasculitis [Figure 2]. In most cases, a skin biopsy is not routinely performed if clinical and 64 serological criteria for scrub typhus are met. However, due to the rare manifestation of this 65 disease, a skin biopsy was done in order to rule out other etiologies of vasculitis in the patient. 66 Hence, the patient was treated with doxycycline 100 mg twice daily. On day 3, improvement of 67 the vasculitis and other symptoms were noticeable [Figure 1B] and the patient was discharged on 68 Day 7 with an additional week of Doxycycline 100 mg twice daily. The patient followed up three 69 weeks later with a significant improvement in his lesions [Figure 1D]. The patient provided 70 informed consent to the publication of this case. 71 72 Discussion 73 Scrub typhus is a common cause of pyrexia of unknown origin in India due to its nonspecific 74 clinical features. It is caused by the organism O. tsutsugamushi which was previously classified 75 under the genus Rickettsia. However, due to different phenotypic and genotypic features, the 76 organism has its own separate genus. In fact, it is a component of the Tsutsugamushi triangle 77 formed by Northern Japan/East Russia (North), Afghanistan/Pakistan (West), and Northern 78 Australia (South). 5 There are three strains of Orientia tsutsugamushi namely Karp, Gilliam, and 79 Kato strains. Infection with one particular strain does not confer immunity to infection with 80 another strain. 5 81 82 The organism enters the human body via the bite of a chigger (trombuculid mite) where it 83 multiplies and then disseminates through the blood and lymph. At the site of inoculation, 84 necrosis of the skin occurs forming a black eschar, which is typical of scrub typhus. However, in 85 the Indian subcontinent, a necrotic eschar can only be detected 10% of the time due to darker 86 skin complexions of the majority of the population and bites located in hidden areas. Hence, 87 serology or a high degree of clinical suspicion based on epidemiological data must be used to 88 guide the diagnosis. 5 89 90 Scrub typhus usually targets a specific population encompassing rural populations predominantly 91 involved in agriculture and those who engage in poor protective personal habits. Moreover, 92 overcrowding plays a huge role in dissemination of the disease as rodents often act as amplifiers 93 of infection. 94 95 O. tsutsugamushi breaches the endothelial cell barrier creating vascular and perivascular lesions 96 that ultimately cause vascular leakage and end-organ damage to multiple organs in the body. 6 97 Once the organism successfully evades the innate human host defenses, various cytokines such 98 as TNF-α, IFN-γ, and M-CSF are produced that results in the multitude of symptoms 99 experienced by the patient. Both humoral and cellular immunity play a role in combating this 100 organism. It involves the production of antibodies against O. tsutsugamushi which can be 101 detected by the WFT and activation of macrophages and helper T cells (Th1) which secrete IFN-102 γ. 6 103 104 The pathophysiology of O. tsutsugamushi causing widespread endothelial damage involves 105 disruption of the adherens junction of the endothelial cells. This results in increased vascular 106 permeability, formation of inter-endothelial gaps, development of actin stress fibers, and change 107 in the shape of the endothelial cells from polygonal to a spindle form. 7 Furthermore, there is also 108 increased vascular expression of nitric oxide and COX-2 expression by the endothelial cells, 109 resulting in the production of prostaglandins. 8 In addition, O. tsutsugamushi multiplies within the 110 endothelial cells and via oxidative stress, destroys the integrity of the blood vessels. 13 This can 111 be established by immunohistochemical staining of endothelial cells which demonstrates rich 112 deposits of the O. tsutsugamushi antigens. 14 113 114 Scrub typhus can present with a few dermatological manifestations that can overlap with other 115 acute febrile diseases. The typical erythematous maculopapular rash and necrotic eschar can 116 point to a diagnosis of scrub typhus, especially in an area of high endemicity. Moreover, the site 117 of the rash can help differentiate between rickettsial diseases. A maculopapular rash distributed 118 across the trunk, sparing the face, palms and soles makes rickettsial spotted fevers an unlikely 119 diagnosis. 12 Other tropical diseases with a similar dermatological presentation include dengue, 120 leptospirosis, enteric fever, malaria, and melioidosis. 9 121 122 Infectious causes of leukocytoclastic vasculitis are most commonly viral in origin such as 123 hepatitis B (polyarteritis nodosa), hepatitis C (mixed cryoglobulinemia), cytomegalovirus, or 124 parvovirus B19. 13 Parasites, bacteria, rickettsia are lesser known culprits of systemic vasculitis. It 125 is paramount to determine the underlying cause of the vasculitis, as this governs the treatment 126 regimen. 13 127 128 The organism is mainly confined to the reticuloendothelial system resulting in 129 hepatosplenomegaly and generalized lymphadenopathy along with other features like fever, 130 myalgia, and a centripetally-distributed maculopapular rash. Complications include acute 131 respiratory distress syndrome, acute renal failure, disseminated intravascular coagulation, 132 meningoencephalitis, myocarditis, pericarditis, and acute hearing loss. It is imperative that 133 serology be done in order to ascertain proper treatment. 9 134 135 WFT is a heterophile agglutination test that can be used to diagnose scrub typhus infection. This 136 test relies on the principle that an antibody triggered by a particular antigen can cross-react with 137 antigens of other species. In this test, antibodies produced by O. tsutsugamushi cross-react with 138 the antigen OX-K of Proteus mirabilis. In our patient, we received a titer of 1:640 which is 139 above the diagnostic titer of 1:320. 15 WFT only tests positive during the 2nd week of illness and 140 has a low sensitivity and specificity as compared to the indirect fluorescent antibody (IFA) test 141 and indirect immunoperoxidase (IIP) test. Even though IFA/IIP are more accurate and precise, 142 WFT is used because of its cost-effective and swift results. 10 A recent case report was published 143 linking a case of Henoch-Schönlein purpura to scrub typhus which used indirect 144 immunofluorescence to confirm the diagnosis (IgM antibody: 1:1024). This is an accurate and 145 precise tool to corroborate the etiology. 16 146 147 The current guidelines for the treatment of scrub typhus include doxycycline 100 mg twice daily. 148 Alternatives such as chloramphenicol, azithromycin, tetracycline, and rifampicin can be used as 149 second-line options. Treatment with doxycycline renders the patient afebrile within 48 hours. 150 Due to the rarity of the necrotic eschar in the Indian population and nonspecific clinical features, 151 a delay in the start of treatment increases the risk of developing complications and causing 152 irreversible damage. As a result, empirical therapy with doxycycline should be started without 153 delay if there is a high degree of clinical suspicion. 11 154 155 Conclusion 156 Scrub typhus remains to be a common zoonotic disease in the Indian subcontinent which is often 157 misdiagnosed or underdiagnosed. This may be due to overlapping clinical features of other 158 tropical diseases, lack of highly sensitive and specific equipment for diagnosis in endemic areas, 159 or delay in presentation. Cutaneous vasculitis secondary to O. tsutsugamushi is an unusual 160 manifestation of this disease and should be considered in endemic areas to avoid delay in 161 treatment. 162 163 Authors’ Contribution 164 AV, RVA and SMP conceptualized the report. KP provided the pathology report of the skin 165 biopsy. VMS analysed the skin findings and performed the skin biopsy. AV drafted the 166 manuscript writing. RVA, RK, AD and SMP reviewed the manuscript and provided intellectual 167 input. All authors approved the final version of the manuscript. 168 169 References 170 1. Lin M, Huang A, Zheng X, Ge L, He S. Misdiagnosis of scrub typhus complicated by 171 hemophagocytic syndrome. BMC Pediatr. 2019 Apr 10;19(1):102. doi: 10.1186/s12887-019-172 1475-x. PMID: 30971222; PMCID: PMC6458710. 173 2. 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BMC Infect Dis 20, 286 (2020). https://doi.org/10.1186/s12879-020-05001-x 210 211 212 213 https://www.ncbi.nlm.nih.gov/books/NBK559225/ Table 1: Laboratory investigations. 214 Lab Investigation Value Normal range Haemoglobin (g/dL) 13.1 13–17 Platelet count (cells/µL) 2,00,000 1,50,000–4,00,000 White blood cell count (cells/µL) 15,300 4,000–11,000 Aspartate transaminase (IU/L) 69 5–40 Alanine transaminase (IU/L) 274 5–40 Alkaline Phosphatase (U/L) 78 40 – 130 Erythrocyte Sedimentation Rate (mm/hr) 2 0–22 C-Reactive Protein (mg/L) 40.92 0–5 215 216 217 Figure 1: Clinical image showing multiple, palpable purpuric lesions arranged in a retiform 218 pattern with a dusky necrotic center and peripheral rim of erythema distributed symmetrically 219 over bilateral lower limbs on day 1 (A) and day 3 (B). A close-up view of skin lesion over the 220 left leg on day 1 (C) and a significant improvement in his lesions on day 21 (D) 221 222 223 Figure 2: Photomicrograph (H&E), (A: X 100) shows dermis with prominent vasculo-centric 224 infiltrate. (B: X 200) shows vessels showing fibrinoid necrosis of vessel walls, dense infiltration 225 of vessel walls by neutrophils with leukocytoclasis. 226