Title: GZ / The Grenz Zone Season 1 / Ep 6
Tags: GZ DermnetNZ

Q: Seborrheic dermatitis is caused by the lipophilic commensal yeast, [...]
Those affected have [...] levels of triglycerides and cholesterol and [...] levels of squalene and FAs in their sebum
A: malassezia furfur (Pityrosporum ovale); higher; low
Back Extra: Lower levels of P.acnes (converts triglycerides to Free FAs which are antimicrobial to malassezia species) are often seen in seb derm patients

Q: Besides seborrheic dermatitis, what can the fungus malassezia cause?
[...], [...], and [...]
A: Neonatal acne; pityriasis versicolor; pityrosporum folliculitis

Q: If you see severe or erythrodermic seborrheic dermatitis in a pt what are some associated disorders?
[...] & [...]
A: Neurologic dz (e.g. Parkinson’s or Epilepsy); HIV/AIDs

Q: When seborrheic dermatitis occurs on the eyelashes, it is referred to as [...]
A: blepharitis
Back Extra: Other causes of blepharitis include
Staph infection
Seb derm/dandruff the eyelid
Ocular rosacea
Infestation of the eyelash by Demodex mite
Contact allergy to substances coming into direct contact with the lid margins

Q: Mild seborrheic dermatitis on the scalp is referred to as [...]
When seborrheic dermatitis is moderate, a thickening plaques may be present (often referred to as [...])
A: dandruff; sebopsoriasis
Back Extra: Sebopsoriasis shown (thicker than normal seb derm, not quite thick enough to be full-blown psoriasis)

Q: How can you differentiate tinea capitis from seborrheic dermatitis on the scalp:
Patients that are often 3-7 y/o, have broken hairs and posterior lymphadenopathy likely have [...]
A: tinea capitis
Back Extra: Patients with seb derm either get the dz as babies (cradle cap) or adults, and lack posterior lymphadenopathy and broken hairs
In addition, may differentiate between psoriasis and contact based on history (new shampoo started) and thorough skin check for nail changes, plaques elsewhere

Q: What disease can be associated with extensive seborrheic dermatitis in an infant?
[...]
A: Leiner's disease
Back Extra: Leiner's disease thought to be associated with a defect in the complement system. May be associated with infections, diarrhea, and failure to thrive

Q: When seborrheic dermatitis occurs in an infant's scalp, it is referred to as [...]
A: cradle cap

Q: Between atopic dermatitis and seborrheic dermatitis, [...] has a later onset at 1-16 weeks and is typically more pruritic and inflammatory vs [...] at 1 week that is less pruritic
A: atopic dermatitis; seb derm
Back Extra: Location on face & flexor surfaces, as well as family hx of atopic triad (atopic derm, allergic rhinitis, asthma) are helpful clues also

Q: Although seborrheic dermatitis is diagnosed clinically, a KOH prep may show the classic [...] appearance, representing the hyphae and spores of malassezia
A: spaghetti and meatballs
Back Extra: Not often performed since it is often unreliably positive
Biopsy may be performed if dx still unclear, and HIV testing may be done if severe/refractory

Q: Although not routinely performed, biopsy of seborrheic dermatitis would show [...], [...], and [...]
A: regular acanthosis; spongiosis; shoulder parakeratosis
Back Extra: Regular acanthosis = regular rete ridge depth + thickened epidermis
Shoulder parakeratosis = parakeratosis is concentrated at the edges of the hair follicles where they reach the epidermis

Q: Mainstay of treatment for seborrheic dermatitis?
[...]
A: Topical antifungals and shampoos
Back Extra: Other treatment options listed below

Triggers for seborrheic dermatitis include fever, immunosuppression, stress, sun exposure, and heat
Back Extra: FISSH

Q: P. acnes converts [...] to [...], which are antimicrobial to malassezia species
A: triglycerides; Free FAs
Back Extra: Thus, an inverse relationship between p. acnes and seb derm exists (another possible theory is that there is only so much "real estate" on the skin of the face and scalp

Q: [...] is a complication of seborrheic dermatitis characterized by pruritic erythematous follicular papules and pustules on the upper trunk, face, neck, or scalp
A: Pityrosporum folliculitis
Back Extra: Typically in sites rich in sebaceous glands in young to middle-aged adults