Title: GZ / The Grenz Zone Season 1 / Ep 9
Tags: GZ DermnetNZ

Q: Which two conditions are classically associated with a "trailing scale"
[...]
[...]
A: Pityriasis rosea; Erythema annulare centrifigum
Back Extra: Scale does not reach the erythematous edge of the lesion
Some say trailing scale faces outwards in PR, inwards in EAC
Resolving pustules/furuncles may also exhibit a trailing scale

Pityriasis rosea clinical presentation
Begins w/ herald patch 70% of the time. Hours to weeks later = diffuse eruption of smaller salmon colored oval and slightly scaly macules, patches and plaques in a “Christmas tree” pattern on the trunk and proximal extremities along lines of skin cleavage
Back Extra: Herald patch

Atypical forms of pityriasis rosea
Papular Pityriasis rosea: More commonly seen in African American children and immunosuppressed patients. May involve face & scalp
Inverse Pityriasis rosea: Affects the intertriginous areas
Oral Pityriasis Rosea: Presents with aphthous-like ulcers

Q: Typical prognosis or pityriasis rosea?
[...]
A: Resolves within 3-8 weeks
Back Extra: Under promising and over delivering may often help these patients. Tell them it will take 8 weeks, they'll be happy if it only takes 4

Q: What would a biopsy of a pityriasis rosea show?
[4 features]
A: Thin mounds of parakeratosis, spongiosis, perivascular lymphohistiocytic infiltrate and extravasated RBCs
Back Extra: Under promising and over delivering may often help these patients. Tell them it will take 8 weeks, they'll be happy if it only takes 4

Causes of pityriasis rosea is typically caused by bugs or drugs:
Viral associations prior to onset of rash (HHV 6 & 7), bacterial
infections (Strep), and drugs, including β blockers, ACE-inhibitors, NSAIDs, and gold
Back Extra: Taking these drugs may cause PR (and lichen planus) to arise, BANG!
Beta
ACE
NSAIDs
Gold

Q: Syphilis is caused by the gram-negative spirochete [...] and the clinical course may be used by following the rule of 3 weeks
A: Treponema pallidum
Back Extra: 3 weeks for 10 chancre to develop after inoculation (painless,
indurated ulcer w/ associated inguinal lymphadenopathy) • Range: 10-90 days
Chancre lasts ~3 weeks
~3 weeks (range 3-10 weeks) after primary chancre appearance, secondary
syphilis rash develops, lasting 3-12 weeks = pityriasiform,
papulosquamous rash
If untreated, latency period lasting months to years before tertiary
syphilis appears w/ gummas, cardiovascular, and neurological changes

Q: The rash of secondary syphilis can appear very similar to pityriasis rosea, but there are 3 key differences
Lesions of syphiis are:
1) [...] compared salmon colored of PR
2) Lack of [...] in 2^o syphilis
3) Can affect [...], whereas these areas are spared in PR
A: Darker copper color; herald patch; palms & soles
Back Extra: Other findings include a prodrome of fatigue, fever, and arthralgia as well as generalized lymphadenopathy, moth eaten alopecia, condyloma lata-like lesions in the mouth and genitals
'

Tinea versicolor, also called pityriasis versicolor, is caused by Malassezia furfur & Malassezia globosa and presents with scattered, hypo-pigmented papules and patches on the upper trunk and proximal extremities w/ scale

Q: Why are the lesions of pityriasis versicolor often hypopigmented when occuring on sun-exposed skin?
Malassezia yeast digest oils on the skin into [...], which [...] = no pigment
A: azelaic acid; inhibits melanocyte melanin production
Back Extra: W/o sun exposure, PV will be tan to red macules patches and plaques w/ scale, and stretching the skin will often help to expose this scale

Q: Pityriasis versicolor (or tinea versicolor) is diagnosed with [...], which may reveal the typical "[...]" appearance
A: KOH prep; spaghetti and meatballs
Back Extra: Representing the hyphae and spores of malassezia

Q: When working up a syphilis diagnosis, you may screen with the non-treponemal tests [...] or [...], which test against a number of antigens including lecithin, cardiolipin, and cholesterol, and can be used to monitor treatment, as well as the treponemal [...] which can be used for confirmation and will remain positive for life
In addition, a biopsy may be performed to aide diagnosis
A: RPR; VDRL; FTA-abs

Biopsy of syphilis lesions include
Acanthosis w/ long thin “phallic” rete ridges, vacuolar interface dermatitis,
neutrophils in stratum corneum, and  plasma cells in dermal infiltrate

Q: Spirochetes of syphilis may also be identified with [...] or Steiner silver stains
A: Warthin Starry

Q: Treatment for pityriasis rosea
[...]
A: Supportive: Resolves on its own in 3-8 weeks
Back Extra: If pruritic, may consider mild topical steroids, oral anti-histamines, UVB, or oral erythromycin (250 mg x4 daily for 2 week duration) may be used as well

Q: What is the treatment for syphilis?
[...]
o If allergic to first line treatment? → [...]
A: Benzathine Penicillin (IM x1 dose @ 2.4 million units); Doxycycline 100 mg BID 14 days
Back Extra: Also patient education:
• Safe sex practice
• Sexual partners should be assessed and treated as well
Be aware of adverse effect: Jarisch-Herxheimer rxn-systemic inflammatory
response occurring in first 24 hrs after penicillin tx. Presents w/ fever, headache, myalgias due to body’s inflammatory rxn to dead spirochetes

Q: What advese reaction do you need to be aware of when treating syphilis, and why does this happen?
[...]
A: Jarisch-Herxheimer rxn-systemic inflammatory response occurring in first 24 hrs after tx w/ penicillin due to body’s inflammatory rxn to dead spirochetes
Back Extra: Presents w/ fever, headache, myalgias, often treated with NSAIDs

OTC shampoos such as selenium sulfide (Selsun Blue), ketoconazole or zinc pyrithione used as body washes
Topical Antifungals: Terbinafine, ciclopirox, or ketoconazole for 2 week course may also be used
Back Extra: Washes-Keep on skin for >5 minutes prior to rinsing
Oral therapy only used if refractory due to hepatotoxic effects: fluconazole x2 300 mg one week apart may be used in these cases
Patient Education:
o Recurrent nature of dz
o Hypopigmented lesions can take months to repigment after tx
o Maintenance therapy, especially during summer months using OTC
body wash x1 every 2-4 week

Q: When are patients more likely to present with pityriasis versicolor (tinea versicolor)?
[...]
A: Summer
Back Extra: Maintenance therapy may involve using OTC body wash x1 every 2-4 week