Title: GZ / The Grenz Zone Season 1 / Episode 13
Tags: GZ DermnetNZ Waikato

Q: Are acids or bases a stronger irritant to the skin?
[...]
A: Bases
Back Extra: Bases both denature proteins in skin and disrupt lipids in stratum corneum
Acids: Sulfuric, hydrochloric, nitric acids
Bases: Detergents, soaps, bleaches, cleaning products

Q: What is a unique feature of subacute eczema that is not a feature of acute eczema?
[...]
A: Scale
Back Extra: Scaling takes time to develop!

Q: A largely characteristic finding of chronic eczema is [...], which occurs due to chronic scratching
A: lichenification
Back Extra: May also have scaling, just like subacute

Q: [...] irritant contact dermatitis occurs after exposure to dust or fibers (fiberglass)
A: Airborne

Q: [...] irritant contact dermatitis is diagnosed when patients complain of a burning sensation without skin changes
A: Sensory

Q: [...] irritant contact dermatitis occurs after exposure to metal or metal like fluids
A: Acneiform

Q: One unique variant of irritant contact dermatitis is [...], in which [...] found in limes, celery, parsley and a host of other plants contacts the skin and is then activated by light, leading to erythema and edema in unique patterns that heal with hyperpigmentation
A: phytophotodermatis; furocoumarin
Back Extra: Seen in spring breakers or bartenders serving margeritas outside in the sun

Q: In addition to bacitracin, neomycin and nitrogen mustard, topical medications that may cause an allergic contact dermatitis include [...] in sunscreen, [...] such as procaine, and topical steroids
A: oxybenzone; ester anesthetics
Back Extra: Lanolin, propylene glycol, and ethylenediamine may be used in cream and ointment vehicles may cause ACD as well

Q: [used in deodorants], [...], and [...] may be used in cream and ointment vehicles and may cause allergic contact dermatitis
A: Lanolin; propylene glycol; ethylenediamine
Back Extra: Watch out for lanolin in the armpits

Q: [...] is made by bees and used in lip balms, and may also cause allergic contact dermatitis
A: Propolis
Back Extra: Watch out for this in ACD of the lips

Urushiol oil in poison ivy, poison oak, and poison sumac causing allergic contact dermatitis is often referred to as rhus dermatitis
Poison ivy, poison oak, and poison sumac are all from the genus toxicodendron within the anacardiaceae family
Back Extra: Tip: If leaves of three, let it be

Q: What is the most common ingredient causing positive patch tests?
[Metal]
A: Nickel
Back Extra: Seen in earrings, belts, and others

Q: Another metal causing allergic contact dermatitis includes [...], which are found in leather, cement, and the green felt on pool tables
A: chromates

Q: Cosmetic Products causing allergic contact dermatitis include [...], [used in perfumes], and [used in hair dye, henna tattoos]
A: fragrance; Balsam of Peru; paraphenylenediamine

The cross reactants for para-phenylenediamine (PPD) can be remembered with the“PASTA” mnemonic
Paraben, Para-aminobenzoic acid (PABA)
Azo dyes
Sulfonamides
Thiazides
Anesthetics (ester)
Back Extra: Formaldehyde is a preservative that may also cause ACD

Q: What causes allergic contact dermatitis on baby’s buttocks?
[used in baby wipes]
A: Methyl-isothiazolinone

Q: [...]-releasing preservatives are another common cause of allergic contact dermatitis
A: Formaldehyde
Back Extra: Quaternium-15 (Dowicil 200): found in soaps, shampoos, moisturizers

Adhesives that may cause allergic contact dermatitis include cyanoacrylates and methacrylate (found in artificial nails), epoxy resin, and p-tert-butylphenol formaldehyde PTBP
Back Extra: PTBP often used to  glue leather products together
Epoxy may be found in: PVC and plastic materials

Q: Rubbers that may cause allergic contact dermatitis include [...], [...] in wetsuits, and [causes shoe dermatitis]
A: latex; neoprene; mercaptobenzothiazole
Back Extra: Watch out for “BACK PASSION” cross-reactant with latex: Bananas, Avocados, Chestnuts, Kiwi, Passionfruit

Cross-reactants with latex include
Bananas
Avocados
Chestnuts
Kiwi
Passionfruit
Back Extra: “BACK PASSION”

Q: [...] is frequently used in nail polish and is a very common cause of eyelid dermatitis
A: Tosylamide
Back Extra: Eyelids have the thinnest skin of anywhere on the body

Q: When using a TRUE patch test, patients have patches removed after 2 days, then return 2-5 days after for their 2nd reading
If the reaction improves in 2nd reading, it’s likely [...] contact dermatitis. If rxn progressively gets worse at 2nd reading, it’s likely [allergic/irritant] contact dermatitis
A: irritant; allergic

Q: The hallmark of contact dermatitis on histology involves [...]
A: spongiosis
Back Extra: Remember this is an eczematous rash
Acute: swelling can be abrupt, forming vesicles and bulla
Chronic: acanthosis (thickening of epidermis)

Q: In comparing allergic vs irritant contact dermatitis on histology, [...] will have more spongiosis and inflammation in dermis, and [irritant/allergic] will also have more “dead-red” keratinocytes
A: allergic; irritant

Q: Treatments for contact dermatitis
[...] – mainstay of treatment
[...] - moderate/severe or refractory disease
[...] may be useful on face and intertriginous areas
A: Topical steroids; Systemic steroids; Topical Calcineurin inhibitors
Back Extra: Most importantly, avoid irritants and allergens