Successful management of third-trimester scorpion envenomation (Parabuthus maximus) in a resource-limited setting: A case report

Abstract

BACKGROUND

Scorpion envenomation in pregnancy is a rare but potentially fatal obstetric emergency, with limited evidence on optimal management and antivenom safety. Neurotoxic venom induces autonomic storms, threatening maternal cardiovascular stability and uteroplacental perfusion, which can lead to fetal distress or demise.

CASE SUMMARY

A 31-year-old gravida 4, para 3 woman at 36 weeks’ gestation presented 30 minutes after a confirmed Parabuthus maximus sting to her right foot. She manifested systemic envenomation, including agitation, profuse sweating, tachycardia (142 bpm), and hypertension (168/102 mmHg). Cardiotocography revealed fetal tachycardia (175-180 bpm). A multidisciplinary team initiated intravenous morphine, midazolam, and species-specific antivenom (South African Vaccine Producers Polyvalent Scorpion Antivenom), resulting in the resolution of maternal and fetal symptoms within 12 hours. Critically, antivenom was administered within 40 minutes of the sting, which likely contributed to the rapid reversal of the catecholamine surge. A key factor enabling this rapid and targeted response was the patient’s action of capturing the scorpion, allowing for precise species identification. The pregnancy progressed uneventfully to term, culminating in an uncomplicated vaginal delivery of a healthy infant.

CONCLUSION

This case illustrates that scorpion envenomation in late pregnancy poses a dual threat to both maternal and fetal well-being. Prompt recognition, continuous fetal monitoring, and the very early administration of antivenom-buttressed by multidisciplinary care-can avert catastrophic outcomes. This case provides supporting evidence that antivenom can be safe and effective during the third trimester, even in resource-constrained environments. Public education on safe first aid, including bringing the scorpion for identification, is essential.

Key Words: Scorpionism; Pregnancy; Antivenom; Resource-limited; Parabuthus maximus; Case report

Core Tip: Scorpion envenomation in pregnancy triggers a dangerous autonomic storm threatening both mother and fetus. We present a successful case of a multigravida at 36 weeks who developed maternal hypertension/tachycardia and fetal tachycardia after a sting by Parabuthus maximus. This case highlights three critical lessons: (1) Scorpion stings are an obstetric emergency requiring immediate fetal monitoring; (2) Early administration of antivenom is a safe and effective definitive treatment in the third trimester and rapidly reverses both maternal and fetal distress; and (3) A coordinated response between obstetrics, toxicology, and critical care is essential to prevent catastrophic outcomes like placental abruption or fetal demise.

INTRODUCTION

Scorpion envenomation is a significant public health concern in tropical and subtropical regions[1]. While general management is established, its occurrence during pregnancy is clinically rare and presents a complex management challenge[2]. The venom of neurotoxic species, such as those in the Parabuthus genus, which is common in East Africa, contains potent neurotoxins that induce excessive autonomic neurotransmission, resulting in a catecholamine surge[3]. This can manifest as hypertension, tachycardia, pulmonary edema, and priapism[4]. In pregnancy, these effects can severely reduce uteroplacental perfusion, potentially causing fetal hypoxia, tachycardia, preterm labor, or even intrauterine fetal demise[5]. Current management literature is limited to case reports and small series, resulting in uncertainty, particularly regarding the use of antivenom during pregnancy. We report a case of third-trimester envenomation by Parabuthus maximus complicated by maternal and fetal tachycardia. It was successfully managed with very early antivenom administration and a multidisciplinary approach in a resource-limited setting, providing further evidence of its potential efficacy and safety.

CASE PRESENTATION

Chief complaints

A 31-year-old woman, gravida 4, para 3, at 36 weeks of gestation, presented with acute severe right foot pain, agitation, and palpitations following a scorpion sting.

History of present illness

The patient was walking barefoot at approximately 07:30 AM when she felt a sudden sharp pain in her right foot. She immediately saw and captured the scorpion, which was later identified as Parabuthus maximus (Figure 1). Within minutes, she developed intense local pain, paresthesia, and warmth at the sting site. Over the next 30 minutes, she developed systemic symptoms including restlessness, profuse sweating, nausea, drooling, and a sensation of her “heart beating out of her chest”. She also reported a notable increase in fetal movements. Before arrival, a family member had applied a dark paste mixture of Kiwi shoe polish and Colgate toothpaste to the wound as traditional first aid (Figure 2).

Figure 1 Photograph of the captured scorpion, identified as Parabuthus maximus, responsible for the envenomation. Note the robust metasoma (tail) and large pedipalps (pincers).

Figure 2 The sting site on the plantar right foot. A 6 cm area of erythema is visible. Note the application of a dark, pasty substance, a mixture of Kiwi shoe polish and Colgate toothpaste, applied as traditional first aid before seeking hospital care. This highlights a critical public health challenge in endemic regions.

The patient had a history of regular menstrual cycles, with her last menstrual period on November 2, 2024 and an estimated date of delivery on August 9, 2025. She had used Depo-Provera as contraception and reported no history of dysmenorrhea. The patient was gravida 4, para 3, with three prior uncomplicated vaginal deliveries.

History of past illness

The patient had no history of chronic medical conditions like hypertension, diabetes, or cardiac disease. No known drug allergies.

Personal and family history

She lives in a region endemic to scorpions (Lodwar, Kenya). She is a homemaker with no history of smoking, alcohol, or substance use and no significant family history of genetic or autoimmune disorders.

Physical examination

On examination, the patient was anxious, agitated, and diaphoretic. Vital signs: Blood pressure 168/102 mmHg, pulse 142 bpm, respiratory rate 24/minutes, temperature 37.8 °C, SpO₂ 98% on room air. Local exam revealed a single puncture wound on the plantar right foot with 6 cm of surrounding erythema and marked hyperesthesia. The cardiovascular exam revealed a tachycardic rhythm with no murmurs. The patient’s lungs were clear to auscultation. Abdominopelvic exams showed a gravid uterus consistent with 36 weeks of gestation, soft, non-tender; fetal lie was longitudinal and presentation was cephalic. The neurological exam revealed hyperreflexia in the right lower limb, without cranial nerve deficits or motor weakness.

Laboratory examinations

Laboratory investigations, including a complete blood count, comprehensive metabolic panel, and inflammatory markers, were within normal limits, except for an elevated C-reactive protein level (75.2 mg/L), a nonspecific finding likely reflecting the systemic inflammatory and stress response to envenomation (Tables 1, 2, 3, and 4).

Table 1 Full hemogram findings.

Parameter	Units	Results	Reference range
WBC	× 109/L	4.69	4.0-10.8
Neutrophils	%	32.8	40-75
Lymphocytes	%	59.9	21-40
Monocytes	%	5.4	3-12
Eosinophils	%	1.4	0.5-5
Basophils	%	0.5	0.5-5
RBC	× 109/L	4.56	4.7-6.1
HB	g/dL	12.6	11.2-16.0
HCT	%	38.3	37.0-47.0
MCV	fL	83.9	76.0-100.0
MCH	Pg	27.5	27.0-31.0
MCHC	g/dL	32.8	32.0-36.0
RDW-C	%	13.8	11.5-14.5
Platelets count	× 109/L	202	160.0-450.0
MPV	fL	9.1	6.5-12.0
PDW	%	15.9	9.0-17.0
PCT	%	0.228	0.108-0.282

RBC: Red blood cells; HB: Haemoglobin; HCT: Haematocrit; MCV: Mean corpuscular volume; MCH: Mean corpuscular haemoglobin; MCHC: Mean corpuscular haemoglobin concentration; RDW-CV: Red cell distribution width - coefficient of variation; MPV: Mean platelet volume; PDW: Platelet distribution width; PCT: Plateletcrit.

Table 2 Liver function test findings.

Parameter	Units	Results	Reference range
Albumin	g/L	36.33	35-52
ALP	U/L	38.1	35-104
ALT	U/L	34.2	0-40
AST	U/L	33.9	0-32
GGT	U/L	6.7	5-36
Total protein	g/L	68.4	66-87

ALP: Alkaline phosphatase; ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; GGT: Gamma-glutamyl transferase.

Table 3 Urea, creatinine, and electrolytes findings.

Parameter	Units	Results	Reference range
Chloride	mmol/L	101.5	95-107
Creatinine	µmol/L	68	44-80
Potassium	mmol/L	3.86	3.5-5.1
Sodium	mmol/L	135.7	135-145
Urea	mmol/L	4.64	2.76-8.07

Table 4 C-reactive protein findings.

Parameter	Units	Results	Reference range
CRP	mg/L	75.2	0-10.0

CRP: C-reactive protein.

Imaging examinations

Abdominopelvic ultrasound: A single viable fetus in cephalic presentation was identified, with an estimated fetal weight appropriate for gestational age. Normal amniotic fluid index. Cardiotocography: Revealed a fetal heart rate baseline of 175-180 bpm (tachycardia) with reduced variability.

MULTIDISCIPLINARY EXPERT CONSULTATION

Given the maternal autonomic crisis and concomitant fetal tachycardia, a multidisciplinary team comprising obstetrics, toxicology, and anesthesia/intensive care unit was convened. The consensus was to administer scorpion-specific antivenom (effective against Parabuthus species) as the definitive treatment for systemic envenomation, along with ongoing supportive care. The availability of the captured scorpion was pivotal in confirming the species and justifying the immediate use of this specific antivenom. The obstetrics team mandated continuous fetal monitoring throughout the crisis.

FINAL DIAGNOSIS

Systemic scorpion envenomation syndrome (due to Parabuthus maximus) with autonomic storm complicating pregnancy at 36 weeks of gestation.

TREATMENT

Treatment was initiated immediately with a multi-pronged approach. Supportive care commenced with intravenous morphine (4 mg) for severe pain, followed by intravenous midazolam (2 mg, repeated once) to manage agitation and autonomic symptoms. As definitive therapy, one vial of intravenous South African vaccine producers polyvalent scorpion antivenom (Batch: SA106; composition: F(ab')2 fragments against Parabuthus, Androctonus, and Buthus species) was administered to neutralize the circulating venom. The rapid clinical improvement can be attributed to the antivenom neutralizing circulating venom antigens, thereby abruptly halting the pathological autonomic discharge. Concurrent obstetric care involved continuous maternal and fetal monitoring. Betamethasone (12 mg intramuscularly) was administered prophylactically to promote fetal lung maturation due to the significant risk of preterm labor precipitated by the envenomation and autonomic stress.

OUTCOME AND FOLLOW-UP

The patient showed dramatic improvement within hours of antivenom administration. Both maternal vitals and fetal heart rate pattern normalized. She was observed for 24 hours with no recurrence of symptoms. She was discharged with routine prenatal follow-up. The pregnancy continued uneventfully to term. She subsequently had a spontaneous vaginal delivery at 38 weeks of gestation of a healthy male infant weighing 3450 g with Apgar scores of 9 and 9 at 1 minute and 5 minutes, respectively. Both mother and baby were well at the 2-week postnatal check as summarized in Figure 3. A pediatrician examined the newborn and showed no signs of adverse neurological or other sequelae. Long-term follow-up for neonatal development was recommended; however, the family was lost to follow-up after the 2-week visit, which is a recognized limitation in this setting.

Figure 3 Flow diagram illustrating the timeline of clinical events. CTG: Cardiotocography.

DISCUSSION

This case highlights the significant clinical and public health challenges posed by scorpion envenomation during pregnancy, particularly in resource-limited settings. Neurotoxic venom from Parabuthus maximus instigates a catecholamine surge that precipitates a maternal autonomic crisis and critically reduces uteroplacental perfusion, culminating in fetal distress[3,5]. In our patient, this pathophysiological sequence manifested as maternal hypertension, tachycardia, and concurrent fetal tachycardia.

Reported outcomes in the literature are markedly heterogeneous (Table 5). Kaplanoglu and Helvaci[6] described a series of exclusively mild envenomations managed with symptomatic care alone, whereas Leibenson et al[7] documented a tragic stillbirth following envenomation in late pregnancy. A critical outcome differentiator appears to be the time to administer definitive therapy (Table 6). Antivenom was administered within 40 minutes of the sting in the present case. This stands in stark contrast to other series, such as Najafian et al[2], where antivenom was given 6-12 hours post-sting and was associated with an 11% rate of neonatal complications. Larger studies from endemic regions like Iran and Tunisia have further correlated delayed intervention with increased rates of miscarriage, preterm birth, and neonatal complications[2,8]. The rapid clinical resolution observed in our patient following early antivenom administration starkly contrasts these adverse outcomes. It reinforces emerging evidence that timely antivenom is the cornerstone of therapy, capable of reversing both maternal and fetal instability[9,10]. While a single case cannot prove universal safety, this finding contributes to the growing body of evidence that robustly challenges historical hesitancy regarding potential teratogenicity or hypersensitivity reactions and strengthens the imperative for its inclusion in obstetric emergency protocols.

Table 5 Literature review.

Ref.	Country	Trimester	Management	Maternal outcome	Fetal outcome
Najafian et al[2], 2020	Iran	All	Antivenom administered 6-12 hours post-sting; supportive care	Stable	11% neonatal complications; Apgar < 8 in 11.3% of preterm births
Ben Nasr et al[8], 2009	Tunisia	All	Supportive care; antivenom use recommended	Stable	Risk of preterm birth, fetal anomalies, and long-term developmental issues
Kaplanoglu and Helvaci[6], 2015	Turkey	All	Symptomatic care (no antivenom)	Stable	All live births
Leibenson et al[7], 2009	Israel	3rd	Supportive care	Stable	Stillbirth
Brown et al[10], 2013	Review	All	Supportive care; antivenom for severe cases	Optimal outcomes with early intervention	Improved fetal outcomes with maternal stabilisation
Present case, 2025	Kenya	3rd	Early antivenom; multidisciplinary care	Full recovery	Healthy neonate

Table 6 Key considerations in scorpion envenomation during pregnancy.

Aspect	Clinical implications
Pathophysiology	Catecholamine-induced uteroplacental vasoconstriction leading to fetal hypoxia
Maternal symptoms	Autonomic storm (hypertension, tachycardia), local pain, potential for severe complications (eclampsia, myocarditis)
Fetal effects	Tachycardia, distress, potential preterm labor or demise in severe cases
Critical management	Prompt antivenom administration, multidisciplinary care, and continuous fetal monitoring
Resource-limited challenges	Antivenom accessibility, harmful traditional practices, and delayed presentation

A pivotal factor in this success was the accurate identification of the scorpion species. The patient's action of capturing the scorpion removed diagnostic ambiguity, allowing clinicians to administer species-specific antivenom confidently and without delay. This highlights a crucial pre-hospital factor: Community education should strongly emphasize that safely capturing and bringing the scorpion (or a clear photograph) to the healthcare facility is a critical step that directly guides life-saving treatment.

Equally critical to the successful outcome was the coordinated multidisciplinary approach. The seamless integration of obstetric, toxicology, and critical care expertise ensured simultaneous maternal stabilization and vigilant fetal monitoring. Such coordination, although logistically challenging in low-resource environments, is crucial in preventing catastrophic sequelae, such as placental abruption or intrauterine demise.

A pivotal, and likely life-saving, factor in this case was the patient's action of capturing and bringing the scorpion to the hospital. This allowed for precise species identification, which is often impossible but crucial for administering the correct, specific antivenom. This stands as a powerful public health lesson. Community education in endemic areas must emphasize this critical yet straightforward action. Furthermore, the documentation of harmful traditional first-aid practices, such as applying shoe polish and toothpaste, underscores a crucial gap in health literacy and highlights the urgent need for targeted community education programs[11]. These programs should integrate evidence-based first aid into routine prenatal care initiatives.

Key first-aid recommendations for scorpion stings:

Do: Clean the wound with soap and water, immobilize the limb, and transport the patient immediately to the nearest medical facility.

Do: If safe to do so, capture or take a clear photograph of the scorpion for identification.

Do not: Apply a tourniquet, incise the wound, attempt to suck out the venom, or apply herbal concoctions, ice packs, or other non-evidence-based substances.

According to the World Health Organization, scorpion stings affect over 1.2 million people annually, leading to more than 3000 deaths, primarily in underserved communities where access to care and correct information is limited[1]. The escalating global burden of scorpionism[1] necessitates strategic investments in the health system to improve antivenom accessibility at peripheral clinics, as reducing treatment delays remains the single most significant modifiable factor for improving outcomes.

This case report is not without limitations. The absence of long-term developmental follow-up for the neonate means potential delayed effects cannot be entirely ruled out, a challenge common in resource-limited settings. Its nature as a single instance precludes definitive conclusions about causality or generalizability. Nevertheless, it adds a significant data point to the scarce global literature by demonstrating that: (1) Antivenom is both safe and efficacious for third-trimester systemic scorpion envenomation; (2) Multidisciplinary care is indispensable for optimizing outcomes; and (3) Community education and decentralized antivenom distribution are crucial pillars for reducing maternal and fetal morbidity in endemic regions.

CONCLUSION

Third-trimester scorpion envenomation by Parabuthus maximus presents a grave threat to maternal and fetal survival. This case irrefutably demonstrates that rapid multidisciplinary intervention coupled with very early administration of antivenom can restore maternal hemodynamics and fetal well-being, ensuring an exemplary outcome. The patient’s action of providing the scorpion for identification was a key link in this successful chain of care. Beyond acute clinical care, addressing pre-hospital delays stemming from antivenom inaccessibility and harmful traditional practices through concerted public health education-focusing on evidence-based first aid and the critical importance of scorpion identification and decentralized toxicology management strategies are essential for endemic regions worldwide.

ACKNOWLEDGEMENTS

The author gratefully acknowledges the clinical staff at Equity Afya, Lodwar, for their exemplary patient care and collaborative spirit throughout this case.