Painful Arm Cont'

Thanks all for your comments

This is latrodectus hasselti (redback widow spider) , one of the species of Latrodectus widow spiders. As mention by Dr Al shukali , it can cause latrodectism although in less severe form compare to the black widow spider. It is available in Oman

Redback spider bite is a common spider envenomation ,as mentioned by most of you , venom of the Latrodectus genus contains Alpha‑latrotoxin. This toxin acts presynaptically to open cation channels (including calcium channels) and stimulate the release of multiple motor end‑plate neurotransmitters and give the clinical manifestations marked by the pain!

Clinical features can be distressing and refractory to symptomatic treatment but not life‑threatening.

Redback spider bites are not initially painful, hence sometimes they may notice the bite!

1. · Intense local pain develops 5–10 minutes after the bite and is followed by sweating and piloerection within an hour. Puncture marks are not always evident and erythema, if present, is usually mild

2. Systemic envenoming can occurs in some patients. Pain typically radiates proximally from the bite site to become regional then general (e.g. pelvic, back, abdominal, chest or shoulder pain). Autonomic features include severe sweating which may be regional (e.g. both legs) or generalised, mild hypertension and tachycardia

3. Other systematic manifestationS may be vomiting , muscles cramps and spasms

untreated, systemic envenoming may follow a fluctuating course lasting 1–4 days.

Treatment is largely supportive :

1. Analgesia including Opioids and sometimes benzodiazepines for the severe pain and spasms

2. Local wound care

3. Antivenom is curative( if available ) specially for severe and refractory symptoms .

References :

1.https://litfl.com/redback-spider-envenoming/

2- Goldfrank”s Toxicologic Emergencies 11 th edition

Black Widow Spider

"The venom is more potent on a volume-per-volume basis than the venom of a pit viper."

- Latrodectus mactans (black widow) is one of 5 species of widow spiders and the classic red hourglass-shaped ventral marking on the abdomen is specific to L. mactans.

- Black widow females are larger, more venomous, and more toxic than black widow males. Their webs are large, irregularly shaped, and typically found by wood piles, barns, sheds, and garages.

The venom is neurotoxic, not cytotoxic!

The major toxic component of widow venom, α-Latrotoxin, results in the massive presynaptic release of several neurotransmitters, including norepinephrine, dopamine, neuropeptides, acetylcholine, glutamate, and γ-aminobutyric acid.

Clinical effects include (as in the case):

• Severe local pain at the site of the bite (which typically migrates proximally)

• Nausea and vomiting

• Abdominal pain

• Hypertension

• Anxiety

• Diaphoresis

• Muscle cramping

• Restlessness

Pain and severe muscle cramping may mimic an acute surgical abdomen. Although symptoms usually resolve within 1-2 days, in cases of severe envenomation, they may persist for several days. Importantly, death has never been reported with isolated Lactrodectus envenomation.

- Laboratory tests are generally not helpful. However, an elevated white blood cell count, lactate dehydrogenase, or creatine phosphokinase may be present.

- Management involves

1. liberal use of benzodiazepines and opioids for muscle spasms and pain control. 70% of patients initially treated with both IV morphine and benzodiazepines obtained symptomatic relief without additional medications. Milder envenomations can be treated with NSAIDs and cold packs.

2. Equine derived antivenin is available and has been shown to reduce the duration of symptoms and reduce hospital length of stay. However, availability is limited due to current manufacturing shortage.

- Antivenom should be considered in cases of respiratory arrest, seizures, uncontrolled hypertension, and pregnancy.

- The administration appears to be relatively safe with mild to moderate adverse effects occurring in only a small percentage of patients. Currently, a new purified F(ab)2 fragment antivenin is undergoing clinical trials and may be a safer alternative to the currently available whole IgG antivenin.

3. Treatment of the local wound should include cleansing and tetanus prophylaxis. Calcium gluconate infusion has long been recommended to reduce symptoms, although evidence for its efficacy is controversial.

This is a dark body with red hourglass back spider, AKA black widow spider. Known to cause manifestations secondary to the release of neurotoxin latrotoxin with clinical local and systemic manifestations that includes:

- Local manifestation: variable severity of muscle ache and pain, erythema and sweating, halo target sign. Pain can be referred to other area depens on the site. Compartment syndrome can rarely happen.

- Systemic Manifestations: generalized muscle spasm, seizure, hypertension, SOB, increased salivation and diaphoresis.

- Management for this patient. That’s a middle aged lady assuming to be othering healthy with local signs.

• Closely monitor airway as these patents might go into respiratory compromise. Also watch for signs of anaphylaxis.

• Tetanus toxoid 0.5 ml IM if TT wasn’t updated.

• Analgesia: opioids and benzodiazepines for severe pain.

• If any evidence of allergy give hydrocortisone

• As patient is hemodynamically stable without much systemic manifestation, not elderly and not pregnant, i will not rush into giving antivenom, her BP and tachycardia can be due to pain. I will give opioids, if pain still i will give benzodiazepines. In case of persisting pain and signs of systemic toxicity antivenom will be given.

• Disposition: if antivenom is given, hemodynamics unstable, i will admit for monitoring and observation of resolving symptoms. If pain improved with opioids and patient remained hemodynamically normal i will observe for 2-3 hours in ED then i will discharge with precautions to come to ed if any manifestations happened.

So this is a 50s old lady who came with history of spider sting. From the picture this is the redback spider one of the species of the black widow spider which can cause lactrodisim although in less severe form.

Patient present with distal pain from sting site and with local reaction, tachycardia and blood pressure looks elevated, she need initially good analgesia start with paracetamol and NSAID. I will do VBG to check electrolytes since lactroducts venom can cause hypocalcemia, I will be carful for any sign of compartment syndrome and check for any 5Ps.

For most cases sually analgesia and close observation at home with good support from relatives can be carried out but patient shows some feature of systemic envinomation, so she need observation at ED, with serial ECG and if vitals and pain controlled can be discharged

The black widow ( Latrodectus)

This patient is showing systemic manifestations( tachycardia , muscle cramps and diaphorisis)

Managment:

Analgesia

TT

Antiveum since the pt is showin early systemic manifestations