Every lid swelling is not stye: A rare presentation of scrub typhus eschar

Abstract

A 17-year-old female patient presented to us with complaints of diffuse swelling in her left upper eyelid with preauricular lymphadenopathy for three days. She was diagnosed with a case of hordeolum externum and was treated on the same line. However, during follow-up, she developed a mild- to moderate-grade fever, which did not subside with treatment. On further investigation, her IgM rapid ELISA for Scrub typhus was positive, which was further confirmed by the Weil–Fellix test (OXK=1:360). She was treated with systemic doxycycline. Within a week, her fever returned to normal baseline, with resolution of local eye lid swelling, and her black scab was also gone. We have reported a case of scrub typhus as a rare manifestation with lid swelling and subsequently eschar formation on the upper eye lid. The patient was promptly treated with oral antibiotics without any morbidity.

Introduction

Our nation is a predominantly warm climate country with a high prevalence of febrile zoonotic/infectious illnesses, with scrub typhus being one of them. This disease is caused by Orientia tsutsugamushi, an obligate intracellular bacterium and is transferred to humans by the bite of a trombiculid mite's larval stage. The mites use rodents as hosts.¹ The common presenting symptoms are fever, headache, myalgia, cough, injected conjunctiva, and gastrointestinal symptoms. An eschar at the bite site, regional lymphadenopathy, and a maculopapular rash may help to diagnose the condition. Despite increased awareness and published publications, the disease can still manifest itself in a variety of unexpected ways. Common ophthalmic presentations are conjunctivitis, keratitis, non-granulomatous uveitis, retinitis, and neuro-ophthalmic symptoms.² We are reporting a very rare presentation of scrub typhus presenting as a stye.

Case report

A 17-year-old female patient reported to us with complaints of swelling and redness in her left upper eye lid for 3 days of duration. It was also associated with diffuse swelling in the preauricular region. No other significant systemic history was present. On examination, her distant visual acuity was 6/6 (both eyes) with full free and painless movement. Local examination showed that diffuse tender swelling covering almost the entire lid with preauricular palpable lymph nodes was present. She was diagnosed as a case of hordeolum externum and an ENT referral was sought in view of the preauricular lymphadenopathy. The ENT examination was within the normal limit. However, she was evaluated for systemic tuberculosis. She was started on local broad-spectrum ciprofloxacin eye ointment twice a day with local hot compresses. She was asked to follow up after 3 days. At her second visit, her swelling in the eyelid remained the same with a slight decrease in her preauricular lymphadenopathy. At that time, the patient had a history of developing mild to moderate fever on and off. Her chest radiograph was normal, Mantoux test was negative. She was started on broad-based antibiotic oral treatment (tablet amoxycillin 500 mg + clavulanic acid 125 mg) empirically with the same local treatment and was again asked for review after 3 days. On her third visit, the patient had decreased eyelid swelling with formation of a local blackish scab in her left upper eyelid (Fig. 1). However, her fever did not subside without the appearance of any new systemic symptoms. Because her fever had not decreased for the past 7 days, she was asked for a medical opinion.

Fig. 1.

Local eye lid swelling mimicking as a stye.

A complete hemogram, blood culture and serological testing for typhoid, dengue serology test, and scrub typhus antigen test were performed. IgM rapid ELISA for scrub typhus was positive, which was further confirmed by Weil–Felix test (OXK = 1:360). The patient also had a slightly abnormal liver function test too. She was promptly started with oral doxycycline (2.2 mg/kg/dose, twice a day) on hospital admission. Within a week, the patient's fever returned to normal baseline with a normal liver function test. Her black scab was also gone (Fig. 2). This finding confirms that the black scab in her left upper eyelid was Eschar, seen in scrub typhus. Patient consent was obtained for images and inclusion in the study.

Fig. 2.

Complete resolution of lid swelling after falling of scab.

Discussion

The scrub typhus mostly affects the younger age group (20–40 years), probably due to increased outdoor activities at this age.³ A female preponderance is also seen.⁴ The vectors of scrub typhus are L. deliense and Leptotrombidium akamushi, which are endemic in certain geographical regions of India. The host of the disease is small rodents, particularly wild rodents.¹ Some species of infective trombiculid mites (“chiggers,” L. deliense, and others) transmit the infection to humans and rodents. They feed on lymph and tissue fluid rather than blood. Once infected in nature by feeding on the body fluids of mammals (e.g. rodents), they keep the infection throughout their life stages. At adults stage, they again pass the infection on to their eggs through a transovarial transmission. Similarly, the infection again passes from the egg to the larva or adult in a process called transstadial transmission. Mite larvae prefer to put their mouthparts down into the hair follicles or pores rather than biting or piercing the skin. Humans become infected when they come into contact accidently with an infective larval mite while walking, sitting, or resting on infested ground. Adult mites go through four stages of development: egg, larva, nymph, and adult. Only larval stage (chigger) capable of transmitting the disease to humans and other vertebrates. The infected patient typically presents with a fever, headache, myalgia, cough, and gastrointestinal symptoms. The severity of the symptoms varies widely, depending on the susceptibility of the host, the virulence of the bacterial strain, or both. As described earlier, fever generally has an abrupt onset with vague symptoms, which mimic viral illness. Fever not subsiding within a week with signs like lymphadenopathy, hepatosplenomegaly requires a detailed systemic investigation. This type of pyrexia of unknown origin reveals that the underlying cause could be scrub typhus.⁵ A vesicular lesion at the site of mite feeding is the earliest symptom of scrub typhus disease in patients, which eventually develops into an eschar or ulcer with regional lymphadenopathy. At the site of the chigger bite, an eschar with a black necrotic centre and an erythematous border appears. It is commonly observed in the groin, axilla, genitalia, and neck. In patients infected with scrub typhus, the frequency of eschar varies from 7% to 80%. It gives a diagnostic sign of disease. A wide variation in ophthalmic signs and symptoms is reported. It ranges from mild conjunctival hyperaemia to neuro-ophthalmic signs.^{6, 7, 8} Opsoclonus is also reported with this disease.⁹ Unilateral optic neuritis and branch vein retinal occlusion are other reported manifestations of the disease.^10,11

We have reported a case of scrub typhus as a rare manifestation with lid swelling and subsequently eschar formation in the left upper eye lid. The patient's systemic complaints developed later, and the patient was promptly treated with oral antibiotics without any morbidity.

Conclusion

The occurrence of eschar in the lid is very rare in this disease. Any lid swelling presenting with fever and lymphadenopathy in the endemic areas should be thoroughly investigated for the underlying cause. It is also suggested that any case of fever with rash should also be evaluated for ophthalmic signs in view of the varied presentations of the disease.

Disclosure of competing interest

The authors have none to declare.