Bites and Neoplasms

YOU IMPRINTED ON MY DAUGHTER

venom

A poisonous substance that is classified by its mechanism of action and can be lethal

neurotoxic, cytotoxic

Types of venom

neurotoxic

What type of venom interrupts nerve conduction?

cytotoxic

What type of venom destroys tissue cells?

rattlesnake

What type of snake is the cause of a majority of the bites in the US?

Dry bite

Makes up 12-20% of the bites in the US characterized by the deposit of no venom.

coral snake

What type of snake has neurotoxic venom (Red touches yellow, you’re a dead fellow)

progessive muscular paralysis due to a blockage of the presynaptic neuromuscular junction

A coral snake bite leads to

No

Are we ever going to put a tourniquet on a snake bite or suck out the venom Chuck Norris style?

pressure dressing, antivenom (5 w/o symptoms, 10-15 w/), intubate

How do you manage a neurotoxic invenomation?

Venom causes respiratory weakness (it paralyzes accessory muscles)

Why do we intubate symptomatic neurotoxin venom victims?

cytotoxic

What type of venom do pit vipers (rattlers, cotton mouths, copperheads) have?

Limb immobilization, antivenom, potential fasciotomy

A patient presents to the ER with a snake bite on her leg. The patient reports the snake had a triangular head and diamonds along its back. On physical exam the bite site is red, swollen, and tender on palpation. Lab work shows thrombocytopenia and prolonged PT (coagulopathy). Whats our treatment plan?

tense and discolored skin, bullae w/in 8 hours, shock, hypotension

A severe cytotoxic bite is characterized by

prevent compartment syndrome and tourniquet affect

Why are fasciotomies a potential treatment option for pit viper bites?

100% (very few can break human skin)

What percentage of spiders in the US are venomous?

diazepam and calcium gluconate with pain management (maybe antivenom)

A patient presents to the ER after being bit by a spider (see image). The bite site is characterized by slight redness and pain. She reports that her muscles feel tight and are starting to ache. Vitals are stable with the exception of a 115 heart rate and a bp of 155/96. What’s the treatment plan?

brown recluse

A patient presents to the ER with a bite wound. On a physical exam, the lesion looks like a sinking pale grey macule surrounded by a halo of tender inflammation. What was our patient bit by?

wound cleanse, Tylenol, excision of necrosis (dapsone/colchine rarely)

Treating a brown recluse bite

Bark Scorpion

What is the most venomous scorpion in the US?

adults if serious symptoms occur, children regardless

When do you give antivenim for bark scorpion stings?

SKs, keloids, Blue nevi, Melanocytic nevi

Types of benign neoplasms

Melanocytic Nevi

Government name for a mole (benign melanocytic growth)

Genetic

The type of melanocytic nevi that is small (<1.5 cm) black or blue with sometimes irregular borders

Acquired

The type of melanocytic nevi that is flat, symmetrical, even borders, maybe raised

junctional nevi

Flat, small, brown lesions at the junction of the epidermis and dermis

compound nevi

Over time if a mole becomes raised and papular is known as a

None

Treatment for melanocytic nevi

50

Patients with more than ______ nevi are at an increased risk for melanoma

blue nevi

A papular blue-black lesion common in patients of Asian descent, more frequently women

keloid

Excessive response to dermal injury characterized local fibroblast proliferation and overproduction of collagen that extends beyond the original site of injury — basically a mega scar

intralesional injection

1st line treatment for Keloids

Melanoma, BCC, SCC

Types of malignant neoplasms

Melanoma

What is the least common skin cancer but most deadly (80% of skin cancer deaths)

tumor thickness

What variable is the single most important prognostic factor in treating melanoma?

Asymmetry, border, color, diameter, evolution

Signs of malignant melanoma (not a nodular one though)?

full-thickness excision biopsy

What is the gold standard for diagnosis and treatment of melanoma?

Mohs Surgery

What is the preferred method of excision in melanoma, SCC, and BCC?

sentinel node biopsy

If melanoma tumor thickness exceeds 1 cm, what do we need to do?

Basal Cell Carcinoma (BCC)

Most common type of skin cancer that is directly related to UV, slow growing with no metastasis, and common in fair skin people?

waxy, pearly appearance with telangiestasia

Describe the typical lesion in BCC

Nodular

What type of BCC is translucent or pearly papules/nodules?

ulcerating

What type of BCC is characterized by a rolled border on an ulcer and crusted?

Sclerosing

What type of BCC is characterized by infiltrating carcinomas and a white patch that is sclerotic in nature with ill-defined borders

superficial

What type of BCC is characterized by red, thin plaques that are scaly with a fined rolled pearly border

pigmented

What type of BCC is characterized by a thick, hard area of pigment that varies

shave, punch

What type of biopsy is used to confirm a diagnosis of BCC or SCC

imoquimod cream, 5-flurouracil

Treatment of superficial BCC

Bowen disease

SCC in situ

Squamous cell carcinoma (SCC)

Erythematous, scaly or rough to the touch, conical or hard nodules that ulcerate with central necrosis related to prolonged skin sun exposure. High risk of metastasis

AK, atypical nevi

Types of premalignant neoplasms

Atypical nevi

Arise on their own or can develop from moles typically are large in nature (>6 mm), ill-define borders, irregular pigmentation

melanoma

Atypical nevi increase the risk of what

surgical excisions of lesion with narrow margins

Treatment of choice for atypical nevi

No histological verification

Why do we never use lasers, cryo, or other methods of tissue destruction on atypical nevi