Seasonal Hyperacute Panuveitis from the highest reported altitude: co-occurrence with scleritis – an unusual presentation

Abstract

Purpose

Seasonal Hyperacute Panuveitis (SHAPU) is a severe, rapid-onset panuveitis primarily affecting children, often linked to the setae released in the air or by contact with female moths of the genus Gazalina (Lepidoptera, Notodontidae), or with their egg masses laid on various substrates. This study aims to report a rare case of SHAPU from the higher altitude of Nepal with an alpine climate, with concurrence of necrotising scleritis. To the best of our knowledge, this is the first report of SHAPU at high elevation.

Case report

A 27-year-trekker male from an alpine climatic region of eastern Nepal was referred to our department, tertiary eye care in Nepal, with a history of sudden onset of redness, pain and decreased vision in his left eye following an indirect contact with a female Gazalina moth resting in his trekking bag during an ascent from 2,364 to 4,371 m above sea level.

Circumcorneal congestion and cells, and flare were observed on clinical examination in the anterior chamber. A necrotising patch was present at the anterior sclera. The details of the lens, vitreous and retina were obscured because of hazy media. Ocular ultrasonography showed hyperechoic shadows in the vitreous with a thickening retina-choroid-sclera complex, suggestive of vitritis. He underwent treatment with antibiotics and steroids via all possible routes (topical, intraocular, periocular and systemic), and the scleral perforation could be prevented, but the visual rehabilitation was not possible.

Conclusion

SHAPU primarily affects the uveal tissue, but its spread of uveal inflammation to the scleral tissue must be borne in mind. This SHAPU case from a high altitude with intense ocular pain suggests new aspects of SHAPU’s pathophysiology, contrasting with its typical painless presentation, warranting further research on the study moth’s habitat at higher altitudes.

Introduction

Seasonal Hyperacute Panuveitis (SHAPU) is a rare yet severe form of panuveitis, known for its rapid onset and visual deterioration. Predominantly affecting children, SHAPU typically manifests as a sudden onset of unilateral redness, hypopyon, leukocoria, hypotony and painless loss of vision, often resulting in blindness and phthisis bulbi [1–3]. While SHAPU cases originate from Nepal’s temperate and subalpine regions, occurrences in the alpine regions are rare [2]. Epidemiological data point to a potential association with Gazalina female moths, locally called Seto Putali, or with their egg masses, with a notable proportion of SHAPU cases reporting physical contact with these insects. Gazalina is a genus of moths included in the Notodontidae family, commonly known as processionary moths, and well-known as agents of public health issues [4]. We herein report an interesting case of SHAPU in an adult male who was trekking to Everest Base Camp and presented with necrotising scleritis following exposure to a Gazalina moth in an alpine climate. This report represents the first documented case of SHAPU at an alpine altitude and its association with scleritis.

Case report

In October 2023, a 27-year-old immunocompetent mountain trekker originally from the Solukhumbu district of eastern Nepal presented with a four-day history of redness, pain, decreased vision and foreign body sensation in his left eye. He was on the trekking route, climbing from Salleri (2,364 m) towards Everest base camp (5,364 m). He had an accidental contact on his face with a white moth, which was resting on his trekking bag during his last night stop at Pheriche, a small village in the Khumbu region of eastern Nepal situated at 4,371 m above sea level. He noted sudden redness, pain, and dramatic loss of sight in the morning. So, he stopped his trek, started climbing down, and was finally rescued by helicopter to Kathmandu on the 3rd day. His friends reported noticing the presence of many Gazalina moths in the region of Namche Bazaar (3,440 m), where these climbers had a stop (Fig. 1).

Fig. 1.

Gazalina moths (male above, female below) observed in September 2023 at an altitude of 2,870 m in Namche Bazar. The moths were found on a wooden infrastructure below the white light source in the night time

On ocular initial examination, his best corrected visual acuity (BCVA) was 6/6 in the right eye, but the left eye had no perception of light (NPL), indicating severe visual impairment. Ophthalmic evaluation revealed circumcorneal congestion, along with cells (+ 2) and flare (+ 2) in the anterior chamber, signifying active inflammation. There was a patch of necrotising scleritis around 2 × 2 mm in the lower nasal quadrant, the blanching test was negative and blood vessels were absent in the necrotic area (Fig. 2).

Fig. 2.

Clinical photograph showing diffuse redness, anterior chamber exudates with white pupil, yellow glow and white patch in the left eye (A). The close-up view in the right-side photo shows the necrotising scleritis in the inferonasal quadrant (B)

Examining the lens, vitreous, and retina was impossible because of the media opacity. The right eye was normal. Ocular B-scan ultrasonography (USG) of the left eye identified hyperechoic shadows within the vitreous and thickening of the retina-choroid-sclera (RCS) complex (Fig. 3A), suggestive of vitritis with attached retina. Specular microscopy revealed a reduced cell density (CD- 641 cells/mm²), increased central corneal thickness (CT- 693 μm) and increase in coefficient of variation (CV − 46%) (Fig. 3B).

Fig. 3.

USG (A + B) scan showing diffuse hyperechoic shadows throughout the vitreous with thickened retina-choroidal complex (A) and Specular microscopy showing the reduced endothelial cell density and increased corneal thickness in the left eye compared to the right eye (B)

Basic investigations of blood (complete blood count, antinuclear antibody test, antineutrophil cytoplasmic antibodies, Human Leukocyte Antigen B27) were ordered. For the microbiological assessment, the swab was obtained from the necrotising site of the sclera and fluids were taken from the anterior chamber and posterior chamber. He was started on topical eye drops like prednisolone, atropine and moxifloxacin. In the meantime, all the blood reports came back normal, and the scleral swab culture along with ocular fluid culture did not yield the growth of any organism.

The consultation was opted for by the infectious and immunology departments. They put him under an intravenous antibiotic (ceftriaxone + metronidazole) and an injection of prednisolone 125 mg OD for three days for the control of scleral necrosis. We also supplemented with the intracameral moxifloxacin injection (0.05 ml) and subconjunctival Inj. Gentamycin + Dexamethasone and intravitreal injection of about 0.1 ml of a combination mixture of intravitreal Triamcinolone acetonide injection (4 mg/0.1 ml), dexamethasone injection (0.4 mg/0.1 ml) and moxifloxacin injection (0.6 mg/0.1 ml) in the operating room with a 30-gauge needle via the par plana route.

The intraocular inflammation started to resolve, but there was a persistence of scleritis, so he received a posterior subtenon injection of triamcinolone acetonide with gentamycin. In a two-week time, his scleritis resolved, aqueous/vitreous reactions decreased, lens was cataractous (Fig. 4), but the vision did not improve from no perception of light and the intraocular pressure was less than 5 mmHg.

Fig. 4.

Clinical photo at discharge showing resolution of congestion and scleritis but the presence of cataractous lens in the left eye

He was under regular follow-up, but after 2 months, he developed a sudden onset of pain with redness in the same eye due to occlusion pupillae with secondary angle closure glaucoma and iris bombe (Fig. 5A) and intraocular pressure of 14mmHg. The surgical peripheral iridectomy was done to release the pupillary block, and the excised iris was sent for histopathological examination which revealed focal areas of exudates (Fig. 5B).

Fig. 5.

Clinical photograph with narrow anterior chamber, iris bombe, pupillary block and cataractous lens (A). The histopathology report at the right shows the section of iris stroma with pigments, vessels, fibroblasts and focal areas of exudates (B)

Later, after 3 months, the aspiration of the cataractous lens was done under local anaesthesia and he was left aphakic, but still he had no perception of light. The patient has been under regular follow-up for a year. However, he still has no perception of light, and the eye is in a state of ongoing phthisis with intraocular pressure < 5 mmHg.

Discussion

This case report of an immunocompetent male trekker of Nepal depicts a unique instance of SHAPU following exposure to a Gazalina female moth during a high-altitude trek. The case is noteworthy for several reasons, particularly the clinical presentation, the challenges in diagnosis, management and complications, and the implications for understanding ocular conditions in high-altitude environments.

Although the primary characteristic of SHAPU is its effect on the uveal tissue, this case shows a worrying extension of inflammation to the scleral region, which is reported for the first time in this case. If prompt treatment is not received, the involvement of the sclera may result in serious consequences, such as scleral necrosis and even perforation, besides the burden of loss of sight [1, 5]. Given the reported severe ocular pain in contrast to the usually painless presentation of SHAPU, the necrotising patch seen in this patient emphasises the importance of vigilance in monitoring scleral involvement in SHAPU cases. A multidisciplinary approach was needed to manage the case, including consultations with infectious disease and immunology specialists. Despite this, the patient ultimately developed complications like cataract formation, secondary angle-closure glaucoma and phthisis bulbi, which needed surgical intervention, but scleral perforation was prevented.

Such case of SHAPU needs to be differentiated from other uveitic conditions like endophthalmitis and ophthalmia nodosa. Endophthalmitis are of two types: exogenous endophthalmitis due to traumatic or surgical insult to the eye and endogenous endophthalmitis secondary to the spread of systemic infection to the eye, usually in an immunocompromised person. Our patient was an immunocompetent trekker with no past and present history of surgical or traumatic intervention, and neither were any organisms were identified in the ocular sample cultures [6]. Hence, endophthalmitis was ruled out.

Conditions like ophthalmia nodosa may mimic SHAPU, where there is an ocular inflammation caused by the penetration of arthropod hairs and setae from caterpillars, or tarantulas into ocular tissues. The ocular inflammation in case of ophthalmia nodosa have insidious onset, milder in type, with localized granulomatous reaction resulting in recurrent or chronic ocular inflammation which are less likely related to visual loss [7]. But in case of SHAPU, onset is sudden with seasonal epidemic panuveitis related to moths’ exposure, resulting in severe non-granulomatous inflammation with fulminant course resulting in permanent loss of vision and phthisis bulbi [2, 3]. And, all these features were present in the present case described.

The idea that insect distribution and abundance may affect the prevalence and severity of SHAPU is further supported by the disease’s seasonal outbreaks, mostly observed in the post-monsoon and early winter seasons [1, 8–10]. An unusual connection between environmental exposure and ocular health is shown in the case of a mountain trekker from Nepal’s Solukhumbu district who experienced serious visual issues after exposure to a Gazalina moth during his mountain journey. Literature has demonstrated that SHAPU is linked to some environmental conditions, like the prevalence of Gazalina moths, especially in Nepal’s mid-mountain areas [3, 9, 10]. Based on a study by Prabin et al., which investigates the correlation between SHAPU cases and Gazalina moth occurrences, it is observed that Gazalina moth abundance is higher at elevations above 2,000 m and specifically noted from March to October in Nepal [11]. Additionally, it has been reported that the seasonal emergence of Gazalina moths coincides with SHAPU cases during odd years in Nepal [11].

SHAPU is documented mainly from Nepal during odd years [1, 3, 9]. However, there are a few sporadic reports from the even years and from Bhutan too [6, 12]. SHAPU cases have been mainly reported from temperate and subalpine regions of Nepal surrounding the district of Kaski [9]. But this trekker’s story also brings attention to the possible risks to one’s eyes that come with travelling in high-altitude areas, where exposure to a variety of environmental elements, such as insects and stressors related to altitude, can cause major health issues. Although alpine regions are characterised by a dry and cold climate, where the Gazalina moth is not reported to occur as their host plants are absent, people like mountain trekkers can be exposed when they move across elevation levels on a short time. This seems to be the case of the observation reported here, as the moth that affected the trekker was likely picked up during a break at lower elevation, where an outbreak has been recorded. During outbreaks, the Gazalina moths emerge simultaneously and aggregate around camp lights, making the accidental contact between moths or their egg masses and people more likely. More research into the ecological effects on human health in mountainous regions is necessary in light of the observed rise in Gazalina moth populations in the Khumbu region during the trek. Hence, this case underscores the necessity for continued research into the pathophysiology of SHAPU, especially regarding the occurrence of habitats suitable to the moths at higher altitudes and their possible participation in ocular inflammation, in addition to highlighting the clinical signs of the condition.

The other uniqueness of this case is the presence of the histopathological finding from the abscised region of the iris, though it was not specific to any aetiology. SHAPU with scleritis could be a mutated version in the form of SHAPU presentation, adding a serious inflammatory threat to the anatomical and visual outcome of the patient. Thus, this case report adds further enigma to the existing knowledge of SHAPU and alerts to an urgent need to crack the mystery of etiopathogenesis. No definitive treatment protocol has been established due to the poorly understood etiopathogenesis of SHAPU. Early reports of SHAPU treatment oscillated between noninfective and infective etiologies, using antibiotics, antivirals, and immunosuppressives, but with poor outcomes due to complications such as retinal detachment and phthisis bulbi [9].

Conclusion

Seasonal Hyperacute Panuveitis (SHAPU) is a severe intraocular inflammatory condition primarily affecting the uveal tissue but can involve the sclera too. It is regarded as a catastrophic ocular disease with cases originating from Nepal’s temperate and subalpine regions. However, people residing in high altitude and alpine regions are also at risk. Early recognition of these atypical presentations is critical for preventing vision loss, and further research is needed to explore the underlying mechanisms of this association.

Thus, this atypical case raises the possibility of a change in the pathophysiology of SHAPU and calls for more research into the biological, climatic and environmental elements influencing these presentations.

Authors’ contributions

Use initials to refer to each author’s contribution, and specify who did what.RKS, AB, PJ, PP wrote the main manuscript text.PK, RKS, PP, DRB prepared figures.AB, SNJ, AKS, MPU supervised the manuscript writing.RKS, SNJ and PP were involved in the patient’s medical and surgical management.All authors reviewed the manuscript.

Funding

This study was done under the financial support of a National Priority Area Research Grant made by the Research Directorate of the Research Coordination and Development Council (RCDC-2078), Tribhuvan University, Nepal.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Ethical approval and consent to participate was obtained from the Nepal Health Research Council (Ref- 190/2023).

Consent for publication

An informed written consent to publish case details and accompanying images was obtained from the patient.

Competing interests

The authors declare no competing interests.