1. A painful swollen thumb
Dr. Law chi yin
PYNEH A&E

2. A painful swollen thumb
A lady age around 60
Sudden severe thumb pain for one hour after stung by a fish spine while preparing the fish for dinner
The fish was caught by her son in the nearby pier
Her son said that the fish was a stonefish

3. A painful swollen thumb
Would you believe him?
Could he catch a stonefish near a pier in Hong Kong?
Was the severe thumb pain due to stonefish envenomation?

4. A painful swollen thumb
On examination:
Blood pressure and pulse were stable
Marked swelling of her left thumb and hand noted
Mild redness and hot only
No foreign body found in the wound

5. The lady’s injury hand

6. The lady’s injury hand

7. The lady’s injury hand

8. Treatment given in A&E ATT Analgesic injection Warm water bath
Kept in observation ward
Symptoms
Vital signs
Monitoring size of swelling
Asked her son to bring back the fish body for examination

9. A painful swollen thumb
Two hours later
The fish body was brought to A&E
The size was just as the length of a tongue depressor
The fish body looked like a stone

10. The secret fish

11. The secret fish

12. The secret fish The color was brown and grey
Mouth and eyes point upward
The dorsal spines were cut by the lady

13. What was the secret fish?

14. stonefish
Identification Guide to Fishes in the Live Seafood Trade of the Asia-Pacific Region.
Published by
WWF Hong Kong
Agriculture, Fisheries and Conservation Department. Hong Kong

15. stonefish stung injury
Swelling and pain persisting despite warm water bath
Skin blister found near puncture site
Swelling extend up to forearm
no muscle weakness, dyspnea and hypotension

16. stonefish stung injury
Blister was clear, no pus
Aspiration done in observation,
Oral ciprofloxacin started

17. stonefish stung injury
Pros and cons of Stonefish antivenom discussed
She refused antivenom for fear of possible allergic reaction

18. stonefish stung injury
Pain and swelling static during observation
She was discharged with oral antibiotic
Follow up 3 days later

19. stonefish stung injury
She came back 10 hours later after leaving A&E
pain and size of bulla increasing
No evidence of tendinosynovitis
Distal pulse and capillary circulation was good
She was admitted to orthopedic ward for puncture site cellulitis

20. stonefish stung injury
Management in orthopedic ward
Wound dressing
IV antibiotic
Patch of superficial skin necrosis noted on day 3, no debridement done
Pain and swelling subsided with conservative treatment
No antivenom given

21. What is stonefish and its venom?

22. Venomous marine fish Family Scorpaenidae Pterois - lionfish
Scorpaena – scorpionfish
Synanceia - stonefish

23. stonefish The most venomous fish in the world
13 dorsal spines contains venom.
The severity of the envenomation depends on the depth and number of penetration

24. stonefish
stonefish envenomation killed many Pacific and Indian Ocean islanders in pre-antivenom period.
1st antivenom developed in 1959

25. stonefish venom 3 deaths reported in the literature
1 case direct intravascular envenomation (Mozambique, 1957)
2 other deaths occurring days or months after envenomation, ? wound infection or tetanus

26. stonefish venom The venom heat-labile proteins
4 biologically active factors:
hyaluronidase fraction
capillary permeability factor
a toxic or lethal fraction (Stonustoxin)
pain producing factor
The 1&2 factors cause edema
The Stonustoxin is myo- and neurotoxic and cause shock

27. What are the clinical features of stonefish envenomation and treatment?

28. Symptoms of envenomation
Systemic effects
Nausea
muscle weakness
Dyspnea
hypotension

29. Symptoms of envenomation
Pain
Immediately localized pain
spread to involve limb in 90 minutes
lasting up to 12 hours if untreated
Mild subsequent pain may persist for days to weeks.

30. Signs of envenomed wound
Discolored by a surrounding ring of bluish cyanotic tissue
Subsequent edema, erythema, and warmth may involve the entire limb
tissue necrosis in the absence of secondary infection (rarely)
Vesicle formation (hands) may be followed by rapid tissue sloughing and cellulitis

31. Tissue reaction of envenomation
Patel and Wells describe 3 grades of tissue reaction in Lionfish envenomation (Pterosis volitans, Family Scorpaenidae)
erythematous reaction
blister formation
dermal necrosis
They have recommended early blister excision to prevent tissue necrosis
The blister fluid contain residual active venom

32. Goal of treatment Control pain Warm water bath Analgesic
Local anesthesia
Antivenom

33. Goal of treatment Wound management
Removal of foreign bodies
Debridement
Prevent infections in high-risk wounds
ATT
IV or oral board spectrum antibiotics

34. Singapore experience
8 cases of stonefish (Synanceia sp.) envenomation in 1.25 years time
Ann Acad Med Singapore 2004;33:515-20
50% cases fish was identify by direct visualization (fish body was brought to A&E )
Caused severe pain and gross edema of the affected limb

35. Singapore experience Treatment given hot water (45ºC) bath analgesia
tetanus prophylaxis
broad-spectrum antibiotics
Specific antivenom is available but not used
Surgical debridement

36. Singapore experience Length of hospital stay averaged 3.9 days
no deaths or systemic morbidity
1 case required surgical debridement for local necrosis
Average time for complete resolution was 8.2 days

37. Singapore experience Conclusions
majority of stonefish envenomations do not result in significant or protracted morbidity
supportive treatment is adequate
Systemic morbidity and mortalities are rare.

38. Is antivenom useful?

39. Stonefish antivenom
Has beneficial effect in relieving the pain of envenomation
40 years of unpublished experience and cases report
Effect of stonefish antivenom other venomous fish sting remains uncertain
J Toxicol Clin Toxicol. 2003;41(3):301-8

40. Australia's Commonwealth Serum Laboratories (CSL Ltd)
The sole manufacturer of antivenoms for human use in Australia. 
Australian antivenoms are amongst the best in the world, in terms of purity and adverse reaction rate

41. stonefish antivenom
It produced by immunizing horses against the stonefish venom
The horse’s serum antibodies is purified and fragmented by a series of digestion and processing steps
It neutralise the effects of the stonefish envenomation

42. Ingredients of the antivenom
It contains 2,000 units of antivenom in 1.5 to 3 mL of liquid.
It also contains
phenol as a preservative
sodium chloride
substances found in horse blood.

43. Indications for antivenom
Severe pain
Systemic features
Shock, weakness, paralysis
large amount of venom
multiple punctures

44. Contra-indication for antivenom
those who have no serious effects of envenomation
Severe allergy reaction to skin test or horse serum product

45. Dosage of antivenom same for both adults and children
It depends on the number of puncture sites from the spines on the stonefish:
1 - 2 punctures the dose is 1 vial (2,000 units)
3 - 4 punctures the dose is 2 vials (4,000 units)
5 or more punctures the dose is 3 vials (6,000 units).

46. Dosage of antivenom
The injection is intramuscularly and can be repeated if necessary.
It is occasionally diluted and injected into a vein.

47. Adverse reaction
Anaphylaxis
Serum sickness

48. Serum sickness of antivenom
Clinical features
Rash
swollen glands
joint pains
fever may
occur anytime in the first 2 weeks after injection
2 cases had been reported after stonefish antivenom

49. Prevention of serum sickness
Pretreatment is advocated
Adrenaline SC/IMI
Antihistamine
Corticosteroid
Skin testing for allergy to antivenom is not recommended, as it is unreliable and may delay urgent therapy

50. Prevention of serum sickness
Corticosteroids delay both the incidence and severity of serum sickness
should be considered if a large volume of antivenom given

51. Marine wound infections
All marine injuries are at risk of secondary infection, antibiotics are recommended
High risk wound
deep puncture wounds
grossly contaminated wounds,
hand and foot (high incidence of ulceration necrosis)
persons who are chronically ill or immunocompromised

52. Marine wound infections
Common bacteria
erysipelothrix rhusiopathiae
mycoplasma marinum
vibrio and aeromonas

53. Erysipelothrix rhusiopathiae (紅斑丹毒絲菌 )
Fish handler's disease
acquired through skin abrasion and minor wound while handling marine animals
especially fish and shellfish
It appears as a well-demarcated cellulitis characterized by erythema, edema, and warmth.
Erythromycin, cephalexin, and penicillin VK are all referenced as appropriate first-line treatment

54. Mycoplasma marinum (海魚分枝桿菌 )
Present with chronic suppurative and granulomatous lesions
After contact contaminated seawater
Local debridement, adequate drainage, and a prolonged antibiotic course (doxycycline, clotrimazole) are essential

55. Vibrio and Aeromonas species
Vibrio species
Vulnificus
Parahaemolyticus
damsela
Aeromonas species
alginolyticus

56. Vibrio and Aeromonas species
The most serious marine infections
may result in the loss of a limb or death
Necrotizing fasciitis
Cellulitis
Myositis
gas gangrene
Sepsis

57. Vibrio and Aeromonas species
Vibrio vulnificus septicemia has a 20-50% mortality
Require IV antibiotic and ICU care
Aeromonas infections may mimic clostridial gangrene.
Antibiotic therapy should be guided by wound swab culture results

58. Stonefish sting: an occupational hazard in Hong Kong
Chan TY, Tam LS, Chan LY
Department of Clinical Pharmacology, CUHK
Ann Trop Med Parasitol Dec;90(6):675-6.

59. Reference websites http://www.emedicine.com/emerg/topic300.htm