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Dermatology Board Prep > DERM (02) Eczematous Disease > Dermatoses due to plants > Flashcards

Dermatoses due to plants Flashcards

1
Q

What are the 4 major plant reaction classifications with subtypes?

A
  • Urticaria (immunologic and toxin mediated [non-immunologic]
  • Irritant dermatitis (mechanical vs chemical)
  • Phototoxic dermatitis (phytophotodermatitis)
  • Allergic Contact Dermatitis
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2
Q

What is the pathophysiology of immunologic contact urticaria

A

Mediated by allergen-specific IgE on mast cells –> mediator release (histamine) since IgE mediated can be a/w anaphylaxis; typically occurs within 30 minutes

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3
Q

Other common causes of immunologic contact urticaria?

A

Potato (m/c) asthamtic response celery (more likely to cause anaphylaxis Raw meat, fish, shellfish

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4
Q

What is oral allergy syndrome?

A

Cross-sensitization to pollen and similar allergens in fruits/vegetable; IgE mediate oral cavity itching, stinging, pain upon eating corss reacting food.

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5
Q

What does birch pollen allergy cross-react with?

A

apples, pears, cherries, peaches, plums, apricots, almonds, celery, carrots, potatoes, kiwis, hazelnuts or mangos. (usually ok when these foods are cooked)

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6
Q

What is more common, toxin-mediated urticaria or immunologic urticaria?

A

Toxin-mediated is much more common

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7
Q

What is the mechanism behind the rash that stinging nettles cause?

A

The sharp hairs on the stinging nettles, called trichomes, contain toxins (histamine, serotonin, and acetylcholine) cause rapid edema, pruritus, and burning.

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8
Q

What is the official name of nettles?

A

Urticacea family: urtica dioica

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9
Q

What is the time-frame of the rash caused from stinging nettles?

A

Wheals achieve maximal size 3 to 5 minutes after contact, and erythema, burning and pruritus last 1-2 hours, persistent tingling for 12+ hours

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10
Q

What member of the urticaceae (nettle family) can kill you?

A

The dendrocnide gneus, gigas, moroides, and photoinophylla species. These are in the rain forests of eastern Australia, potentially deadly stings.

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11
Q

What is the common causes of mechanical irritant dermatitis from plants and what is the mechanism?

A

Mechanism: larger spines or smaller glochids (short barbed hairs) cause penetrating injuries and inoculation of bacteria.

Common causes: opuntia species (prickly pear)

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12
Q

What bacteria are inoculated in injuries from pountia species (prickly pear)

A

C. Tetani, S. Aureus, S schenkii, and atypical mycobacteria

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13
Q

How do you remove spines from opuntia species injury?

A

Remove larger pieces with tweezers, then use glue and gauze for smaller pieces. After the glue has dried the guaze was grasped and peeled off, resulting in the removal of 95% of implanted glochids

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14
Q

Name different plant things that can cause penetrating injuries and the microorganisms associated with it?

A
  • Spines and thorns: clostridium tetani, staphlococcus aurerus
  • Grassess, sphagnum moss, rose thorns: sporothrix schenckii
  • Blackberries: mycobacterium kansasii
  • cactus spines: mycobacterium marinum
  • spiky tropical vegetation: mycobacterium ulcerans
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15
Q

What is the chemical that causes chemical irritant dermatitis in garlic (allium sativum) family: alliaceae

A

Thiocynates (bulbs)

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16
Q

What is the chemical that causes chemical irritant derm in daffodils/narcissus flowers (narcissus spp, family amarylidaceae)?

A

Calcium oxalate (stems, leaves, bulbs)

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17
Q

What is the chemical that causes chemical irritant derm in brassicaceae family? (brassica nigra, or black mustard and raphanus sativus, or radish)

A

Thiocyanates

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18
Q

What are the chemicals which cause irritant derm in the bromeliaceae family? (ananas comosus, or pineapple)

A

Bromelain (stem>fruit) Calcium oxalate (all parts)

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19
Q

What causes irritant derm in polygonaceae family plants (rheum rhaponticum or rhubarb)?

A

calcium oxalate (leaves)

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20
Q

What is the most common cause of daffodil itch, or the most common cause of ICD in florists?

A

Calcium oxalate (stems, leaves, bulbs) found in daffodils (narcissus spp) family amarylidaceae

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21
Q

What plants have calcium oxalate in them, potentially causing ICD?

A

daffodil, dumb cane, philodendron, pinapple, hyacinth, rhubarb

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22
Q

What clinical manifestations can the thiocyantates found in garlic bulbs cause?

A

High concentrations can lead to 2nd -3rd degree burns and subungal hyperkeratosis and hemorrhage that can mimic nail psoriasis

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23
Q

What plants have phorbol esters which can cause ICD?

A

Family euphorbiacea, croton plant, leafy spurge, manchineel tree, and poinsettia

24
Q

How do the family ranunculaceae (buttercups and marigolds) cause ICD?

A

These contain the glycoside ranunculin that is converted to protoanemonin after plant injury. So this is only in freshly damaged plants caused reactions, this is becuase it is rapidly polymerized to non-irritant anemonin. -the protoanemonin causes severe, linear vesiculation that may resembelearly phytophotodermatitis but wihtout hyperpigmentation.

25
Q

How does capsaicin work?

A

When capsaicin from the pepper (solanacea) contacts the skin it depolarizes nerves causes vasodilation, smooth muscles stimulation, glandular secretions and sensory nerve activation leds to burnign sensation and erythema.

26
Q

What is a phototoxic reaction?

A

Consists of erythema and blistering and delayed hyperpigmentation following exposure to plants. -topical or oral photosensitizing agent + UVA light (320-400nm) = phytophotodermatitis

27
Q

What types of chemicals can cause phytophotodermatitis?

A

Furocoumarins possess linear (psoralens) or angular (angelicins) tricyclic structures. -Bergapten (5-MOP) and 8-MOP (xanthotoxin) cause the most severe reactions -Furocoumarins appear necessary to defend plants from fungal attack

28
Q

Mechanism of how psoralens cause phytophotodermatits?

A

In the presence of UVA (320-400nm), desmosomal plaques detach and degenerate leading to blister formation wihtout the need for DNA damage. -the UVA also excites intercalated psoralens to form covalent interstrand DNA corss-links by binding to pyrimidines. this leads to further keratinocyte cell deaht (apoptosis sunburn cells) and stiumlates hyperpigmentation via increased melanocyte mitosis and dendricity, melanocyte hypertrophy, increased tryosinase activity, larger melanosomal size, and enhanced distribution of mealnsomes thorughout the epiderms

29
Q

When is the skin at peak sensitivity to UVA light after contact with furocoumarins?

A

Peaks 30-120 minutes after contact with furocoumarins

30
Q

Key to clinical configuration of phytophotodermatitis?

A

Bizarre configurations of erythema, edema and bullae appear after 24 hours and peak at 72 hours Hyperpigmentation appears 1–2 weeks later and lasts months to years Occasionally, low-dose UVA and/or psoralens cause hyperpigmentation without a preceding vesicular or erythematous eruption

31
Q

What are plants that cause phytophotodermatitis in the apiaceae/umbelliferae family?

A

So think of an ape holding an umbrella for this cause of phytophoto -Strimmer dermatitis: hogweed (heracleum), cow parsley, and wild chervil -harvester’s dermatitis in gardeners: parsley, parsnips, celery, carrots

32
Q

What is the appearance of the apiaceae/umbelliferae family?

A

Flowers easily identified as they are clustered on a stalk and arise from a single point.

33
Q

What plants are in the family Rutaceae that cause phytophotodermatitis

A

-Citrus (lemon, lime, grapefruit), rue -Citrus bergamia (bergamot orange) perfume -Pelea anisate (hawaiian leis)

34
Q

Plants in the maraceae family that cause phytophotodermatitis?

A

Fig and fig leaves mulberry

35
Q

Plants in the fabaceae family that cause phytophotodermatitis?

A

Bavachee/scurf pea (used as vitiligo treatment) Balsam of Peru (Myroxylon balsamum, Myroxylon pereiae)

36
Q

What is the allergen in the anacardiaceae family, toxicondendron species (poison ivy, oak, sumac)

A

Urushiol (an oleoresin)

37
Q

What is the sensitizing ingredient for urushiol?

A

Pentadecylcatechol

38
Q

What plants also have urushiol or sensitizing agents?

A
  • cashew nut tree (anacardium occidentale) in oil in middle of nut shell
  • mango tree (Mangifera indica)
  • Brazilian pepper tree or Florida holly (shinus terebinthifolius)
  • ginkgo tree (Ginkgo biloba)
39
Q

What if urushiol stains clothing black, what is the significance of this for patients?

A

It cannot be washed off and will retain its allergenicity indefinitely.

40
Q

When must you wash your hands for poison ivy?

A

As soon as possible! -after 15 minutes you can only get off 25% of urushiol.

you also want to use soap after initial rinsing, early use of soap or alcohol will enhance resin permeability since these are better solvents for urushiol than water.

41
Q

What are some plants and plant products that can lead to erythema multiforme in the setting of severe allergic contact dermitits?

A
  • poison ivy, oak sumac
  • Tea tree oil (melaleuca alternifolia)
  • Wild feverfew (parthenium hysterophorus)
42
Q

What is a major cause of airborne contact dermatitis among plants?

A

Asteraceae (compositae). These include daisy (leucanthemum spp), cushion chrysanthemum (X Dendranthema cvs)

43
Q

What are the major sensitizers in asteracea (compositae)

A

sesquirterpen lactones which are found in the leaves stems and flowers

44
Q

What is the difference between photosensitive dermiatitis and airborn allergic contact?

A

Airborne ACD involves the eyelids/melolabia folds/submenta/retroauricular sulci/antecubital fossa

45
Q

What are some of the most common plants invovled in airborn ACD in the asteraceae (compositae) family?

A
  • American ragweeds (amborsia spp)
  • Dandelion (Taraxacum officinale)
  • Chrysanthemum (X Dendranthema cultivars)
  • Sunflower (Helianthus annuus)
  • Endive (chicorium endiva)
  • Globe artichoke (Cynara scolymus)
  • Lactuca sativa (Lettuce)
46
Q

What is the treatment fo anacardiaceae and asteraceae dermatitis?

A

DO NOT: use topical anithistamines, anesthetics containing benzocaine, topical antibiotics to prevent sensitizaiton. Topical steroids adn calcineurin inhibitors are not effective. this can all cause sensitization -oral antihistamines not helpful -oral pred shoudl be 1-2mg/kg/day, do not use medrol dosepak (rebound) -Can use intramuscular long-acticing triamcinolone acetonide (1mg/kg) mixed with fast activing betamethasone (.1mg/kg) -prevention: ivy-block in patch test positive individuals. Must wear vinyl gloves (poison ivy pentrates through rubber gloves).

47
Q

What type of plants have bromelin and what type of contact dermatitis does it cause?

A

ICD

Pineapples

48
Q

What type of plants have calcium oxalate and what type of contact dermatitis does it cause?

A

ICD

Amaryllidaceae/Liliaceae: Daffodil, hyacinth, and tulip bulbs

Araceae: Dumb cane

Ananas comosus: pineapple

49
Q

What profession commonly gets ICD from calcium oxalate?

A

Florists –> daffodil itch

50
Q

How do you treat ICD from capsaicin?

A

Neutralize with acetic acid (vinegar) or antiacids

51
Q

What type of plants have phorbol esters and what type of contact dermatitis does it cause?

A

ICD

Euphorbiacea: Croton plant, spurges, and poinsettias

also have latex

52
Q

What systemic illness can Euphorbiaceae family plants cause?

A

These have phorbol esters

These can cause temporary blindness

53
Q

What type of plants have protoanemonin/ranunculin and what type of contact dermatitis does it cause?

A

ICD

Ranunculaceae: Buttercups and marigolds

54
Q

What distinctive skin findings can Ranunculaceae plants cause?

A

(buttercups, marigolds)

Classic linear vesicles like phytophotodermatitis but no hyperpigmentation

55
Q

What type of plants have thiocyanates and what type of contact dermatitis does it cause?

A

ICD

Alliacea: garlic

Brassicaceae: Black mustard, radish

56
Q

What plants cause phytophotodermatitis?

A

Apiaceae: cow parsley, wild chervil, parsley, parsnips, celery, and carrots

Rutaceae: Citrus (lemon, lime, grapefruit), bergamot orange (berloque dermatitis), Pelea anisate (Hawaiian leis)

Moraceae: fig and fig leaves, mulberry

Fabaceae: BAvachee/scurf pea, Balsam of Peru

DERM (02) Eczematous Disease (6 decks)

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