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derm.pityriasis-rosea.core.v1PRODUCTION
derm.pityriasis-rosea.core.v1

Pityriasis rosea

dermatologysubacuteadultpediatric
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12/12 authored

Canonical 12-phase frame with authored status for this dossier.

Current phase

Frame

Detailed

Frame PR as a common, self-limited, presumed-viral (HHV-6/7) papulosquamous eruption — the dominant clinical task is CONFIDENT DIAGNOSIS + RULING OUT SECONDARY SYPHILIS, not pharmacotherapy. Most cases resolve in 6-8 weeks with reassurance + symptomatic care. Atypical, palm/sole, mucosal, recurrent, or pregnancy-onset cases need active workup. The not-to-miss is secondary syphilis masquerading as PR.

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PR vs syphilis vs drug-eruption framing set; pregnancy + duration thresholds noted

Patient inputs (12)

Trunk / proximal limbs with Langer cleavage-line orientation (Christmas-tree on back); sparing face / palms / soles in CLASSIC PR — atypical involvement (palms / soles / inverse) raises syphilis suspicion (Mashoudy PMID 39798062)

A documented herald patch 1-2 wk before the generalised eruption strongly supports PR (~50-90%); absence does NOT rule PR out but lowers the prior (Drago PMID 19615540)

Any sexually-active patient with risk factors (new partner, MSM, prior STI, sex worker, HIV) -> syphilis serology regardless of palm/sole involvement; PR is a common late-secondary-syphilis mimic (Drago PMID 19615540)

Pityriasiform drug eruptions and post-vaccine PR-like eruptions mimic classic PR; the temporal drug/vaccine link + ddx histology pivot management (Drago PMID 19615540; Durgin J Cutan Pathol 2024 PMID 39021288)

PR in first 15 gestational weeks shows an observational signal for miscarriage / preterm delivery (Drago JAAD 2008 PMID 18489054); gates pregnancy-specific counselling and OB follow-up

Oval salmon-pink plaque with peripheral collarette of scale and central clearance is the morphologic signature — drives the dx vs syphilis / nummular eczema / tinea / guttate psoriasis branch (Drago JAAD 2009 PMID 19615540)

Duration >12 weeks or recurrence prompts re-evaluation (atypical PR persistent form, pityriasis lichenoides chronica, drug-induced eruption, mycosis fungoides masquerading) — biopsy + RPR threshold lowered (Mashoudy PMID 39798062)

Palm/sole involvement, mucosal patches, condyloma lata, or generalised lymphadenopathy mandate immediate syphilis serology — secondary syphilis is the not-to-miss mimic of PR (Drago PMID 19615540)

Itch dominance and sleep disruption drive symptomatic management (topical steroid + oral antihistamine + reassurance) (Mashoudy PMID 39798062; Ciccarese PMID 39597810)

Mandatory in atypical PR, sexually-active patients with risk, and ANY palm/sole involvement; a non-treponemal (RPR/VDRL) + treponemal (FTA-ABS/TPPA/EIA/CIA) pair is the standard PR-vs-secondary-syphilis discriminator (Drago PMID 19615540)

KOH scrape of a scaly plaque rules out tinea corporis (PR mimic) when needed; clinical pivot is the herald-patch + Christmas-tree distribution (Mashoudy PMID 39798062)

Baseline only when an alternative diagnosis (syphilis, drug eruption, pityriasis lichenoides) is being investigated or systemic symptoms are pronounced — not routine for classic PR

* = hard-required. Engine cannot meaningfully run until these are filled.

Severity triggers (5)

5 need judgement
  • informationalseveresecondary_syphilis_mimic_palm_or_sole_or_mucosa
    PR-like eruption with palm or sole involvement, mucous patches, condyloma lata, generalised lymphadenopathy, or any sexually-active patient with STI risk (Drago JAAD 2009 PMID 19615540)
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalseverepregnancy_with_first_trimester_pr
    PR developing in the first 15 gestational weeks (Drago JAAD 2008 PMID 18489054)
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalmoderatepersistent_atypical_eruption_over_12_weeks
    PR-like eruption persisting > 12 weeks, with atypical / fixed / poikilodermatous morphology, or recurrence (Mashoudy 2025 PMID 39798062)
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalmoderatepityriasiform_drug_eruption_temporal_link
    PR-like eruption arising within weeks of a new medication or vaccine (ACE-inhibitor, hydrochlorothiazide, omeprazole, terbinafine, lamotrigine, barbiturate, biologic, TKI such as imatinib, COVID-19 vaccine, etc) (Drago PMID 19615540; Durgin J Cutan Pathol 2024 PMID 39021288)
    Trigger could not be auto-evaluated — needs clinician judgement.
  • informationalmoderateimmunosuppressed_or_unusual_demographic_atypical_pr
    PR-like eruption in an immunosuppressed patient (transplant, HIV, biologic, chemotherapy) or in an unusual demographic (very young child / elderly) (Mashoudy PMID 39798062)
    Trigger could not be auto-evaluated — needs clinician judgement.

Workflow calculators

This dossier does not reference any calculators.

Recommended regimen

Pityriasis rosea — reassurance + stepwise symptomatic ladder (Drago JAAD 2009 / 2008; Mashoudy 2025; Ciccarese 2024)
axis: pr_symptomatic_ladderstep 1 - Step 1 — Reassurance + barrier care (every patient)
Selected step "Step 1 — Reassurance + barrier care (every patient)" — Every confirmed PR patient — the dominant intervention regardless of severity
  • patient_education_and_reassurance_self_limited_course
    first line
    patient_education
    Drago JAAD 2009 (PMID 19615540); Mashoudy 2025 (PMID 39798062) — PR is self-limited; resolves in 6-8 wk (range 2-12 wk); recurrence ~3%; not contagious in the usual contact sense; post-inflammatory pigment change is benign and self-limited; this is the most important intervention.
  • gentle_emollient_and_skin_care
    first line
    barrier_repair
    Mashoudy 2025 (PMID 39798062) — gentle non-soap cleanser, lukewarm short baths, daily emollient reduce dryness-driven itch and accelerate symptomatic recovery.
  • avoid_unnecessary_antivirals_and_antibiotics_in_classic_pr
    first line
    deprescribing_rule
    Ciccarese 2024 (PMID 39597810) and standard derm practice — antibiotics have NO role in classic PR; antivirals are optional and not first-line; reserve for severe / symptomatic / atypical cases.

outpatient playbook — drug actions (4)

  1. 1. patient education + emollient + gentle skin care (all patients)
    self-care • topical / behavioural • daily
    trigger: Confirmed PR diagnosis (Drago PMID 19615540)
    The most important intervention; PR resolves in 6-8 wk
  2. 2. triamcinolone 0.1% cream BID short course (itchy plaques on trunk/extremity)
    rxcui 10759
    0.1% • topical • BID for ~1-2 weeks
    trigger: Itch disrupting sleep or daily activities (Mashoudy PMID 39798062)
    Mid-potency topical steroid relieves inflammation + itch; limit duration to avoid atrophy
  3. 3. cetirizine 10 mg PO daily (daytime itch); hydroxyzine 25 mg PO at night (sleep)
    rxcui 20610
    cetirizine 10 mg • PO • once daily
    trigger: Pruritus disrupting daytime / nocturnal function (Mashoudy PMID 39798062)
    Oral H1 antihistamine for symptomatic itch relief; second-gen non-sedating preferred for daytime
  4. 4. nbUVB phototherapy OR aciclovir 800 mg 5x/d x 7 d (severe extensive disease)
    rxcui 281
    phototherapy 2-3x/wk; aciclovir 800 mg • phototherapy / PO • phototherapy 2-3x/wk; aciclovir 5x/d
    trigger: Severe symptomatic extensive PR poorly controlled by topicals + antihistamine (Ciccarese PMID 39597810; Mashoudy PMID 39798062)
    Phototherapy ranked best for accelerated resolution by some reviews; aciclovir ranked highest for rash improvement in network MA — both are second-line

Auto-drafted A&P note

outpatient

Subjective

- Possible entry pathways: Solitary oval scaly plaque (herald patch) 1-2 weeks before a generalised eruption of smaller oval scaly papules on the trunk and proximal limbs (classic PR; Drago JAAD 2009 PMID 19615540); Generalised eruption of salmon-pink oval papules and plaques following Langer cleavage lines (Christmas-tree on the back) with peripheral collarette of scale (Drago JAAD 2009 PMID 19615540); Pruritic generalised eruption preceded by mild constitutional prodrome (fever, headache, malaise, arthralgia, lymphadenopathy) in young adult / adolescent (Mashoudy Am J Clin Dermatol 2025 PMID 39798062).

Objective

- No vitals, labs, or imaging entered for this encounter.

Assessment

**Pityriasis rosea** (derm.pityriasis-rosea.core.v1).
Phenotype framing: Terminal differential with named pivots: PR vs SECONDARY SYPHILIS (palm/sole involvement + mucous patches + lymphadenopathy + RPR-reactive pivot — the not-to-miss; mandatory rule-out) vs nummular eczema (well-defined coin-shaped plaques without collarette pivot; itch-dominant; chronic course) vs tinea corporis (annular advancing scale with central clearing, KOH-positive pivot) vs guttate psoriasis (post-streptococcal; smaller papules with thicker silvery scale; no herald patch; scalp + nail pivot — route derm.psoriasis.core.v1) vs pityriasis lichenoides chronica (chronic course with varied lesion ages; biopsy pivot) vs PITYRIASIFORM DRUG ERUPTION (temporal drug link, eosinophils + necrotic keratinocytes on biopsy — route derm.drug-eruption.core.v1) vs atypical viral exanthem (Gianotti-Crosti, viral exanthem of childhood) vs mycosis fungoides (chronic / fixed / poikilodermatous — biopsy mandatory). Always biopsy a persistent / atypical / treatment-resistant case before assuming PR.
Scope: Frame PR as a common, self-limited, presumed-viral (HHV-6/7) papulosquamous eruption — the dominant clinical task is CONFIDENT DIAGNOSIS + RULING OUT SECONDARY SYPHILIS, not pharmacotherapy. Most cases resolve in 6-8 weeks with reassurance + symptomatic care. Atypical, palm/sole, mucosal, recurrent, or pregnancy-onset cases need active workup. The not-to-miss is secondary syphilis masquerading as PR.

No severity triggers fired against current inputs.

Plan

Regimen axis: **Pityriasis rosea — reassurance + stepwise symptomatic ladder (Drago JAAD 2009 / 2008; Mashoudy 2025; Ciccarese 2024)** — step "Step 1 — Reassurance + barrier care (every patient)".
1. patient_education_and_reassurance_self_limited_course (patient_education, first line) — Drago JAAD 2009 (PMID 19615540); Mashoudy 2025 (PMID 39798062) — PR is self-limited; resolves in 6-8 wk (range 2-12 wk); recurrence ~3%; not contagious in the usual contact sense; post-inflammatory pigment change is benign and self-limited; this is the most important intervention.
2. gentle_emollient_and_skin_care (barrier_repair, first line) — Mashoudy 2025 (PMID 39798062) — gentle non-soap cleanser, lukewarm short baths, daily emollient reduce dryness-driven itch and accelerate symptomatic recovery.
3. avoid_unnecessary_antivirals_and_antibiotics_in_classic_pr (deprescribing_rule, first line) — Ciccarese 2024 (PMID 39597810) and standard derm practice — antibiotics have NO role in classic PR; antivirals are optional and not first-line; reserve for severe / symptomatic / atypical cases.

Setting playbook (outpatient) — Confirm PR clinically, actively rule out secondary syphilis in any atypical / palm-sole / sexually-active / pregnant / persistent case, reassure that PR is self-limited (6-8 wk), provide symptomatic relief proportional to itch + QoL impact, and reserve antivirals/phototherapy for severe disease (Drago JAAD 2009 PMID 19615540; Mashoudy 2025 PMID 39798062; Ciccarese 2024 PMID 39597810; Drago JAAD 2008 PMID 18489054)
4. patient education + emollient + gentle skin care (all patients) self-care topical / behavioural daily — Confirmed PR diagnosis (Drago PMID 19615540) (The most important intervention; PR resolves in 6-8 wk)
5. triamcinolone 0.1% cream BID short course (itchy plaques on trunk/extremity) 0.1% topical BID for ~1-2 weeks — Itch disrupting sleep or daily activities (Mashoudy PMID 39798062) (Mid-potency topical steroid relieves inflammation + itch; limit duration to avoid atrophy)
6. cetirizine 10 mg PO daily (daytime itch); hydroxyzine 25 mg PO at night (sleep) cetirizine 10 mg PO once daily — Pruritus disrupting daytime / nocturnal function (Mashoudy PMID 39798062) (Oral H1 antihistamine for symptomatic itch relief; second-gen non-sedating preferred for daytime)
7. nbUVB phototherapy OR aciclovir 800 mg 5x/d x 7 d (severe extensive disease) phototherapy 2-3x/wk; aciclovir 800 mg phototherapy / PO phototherapy 2-3x/wk; aciclovir 5x/d — Severe symptomatic extensive PR poorly controlled by topicals + antihistamine (Ciccarese PMID 39597810; Mashoudy PMID 39798062) (Phototherapy ranked best for accelerated resolution by some reviews; aciclovir ranked highest for rash improvement in network MA — both are second-line)

Non-pharmacologic actions:
- Mandatory secondary-syphilis exclusion (RPR + treponemal test) in any atypical / palm-sole / sexually-active / pregnant / persistent case (Drago PMID 19615540)
- Pregnancy + first-15-week onset -> OB referral + medication review (Drago PMID 18489054)
- Drug-temporal-link review and screen for pityriasiform DRUG eruption (route derm.drug-eruption.core.v1 if positive)
- Reassurance counselling: 6-8 week course, ~3% recurrence, post-inflammatory pigment change is benign
- Biopsy for persistent (>12 weeks) / atypical / treatment-resistant cases — exclude mycosis fungoides + pityriasis lichenoides chronica
- Avoid unnecessary antibiotics + unnecessary systemic corticosteroids in classic PR

AVOID / contraindication checks:
- Do not call it pr without ruling out secondary syphilis (palm/sole involvement, mucous patches, condyloma lata, generalised lymphadenopathy, or any meaningful STI risk  > mandatory RPR + treponemal serology before labelling PR — secondary syphilis is the dominant harm in this differential; Drago JAAD 2009 PMID 19615540)
- No antibiotics for classic pr (PR is presumed viral HHV 6/7 reactivation; antibiotics are inappropriate unless an alternative bacterial diagnosis is established; Ciccarese 2024 PMID 39597810)
- Antivirals not first line only severe or atypical (aciclovir / valaciclovir are optional second line for severe disease — evidence base is small RCTs and not strong enough for routine use; Ciccarese PMID 39597810)
- Limit topical corticosteroid duration and bsa (use mid potency BID short course on trunk/extremity only; low potency on face/folds; avoid prolonged or large area use to prevent atrophy)
- Pregnancy first 15 weeks pr needs ob input (Drago JAAD 2008 PMID 18489054 — observational signal for miscarriage / preterm delivery; OB referral; review for drug induced PR like eruption; avoid avoidable systemic agents)
- Do not give systemic corticosteroids routinely (rebound worsening reported; reserve for genuinely severe extreme pruritus cases unresponsive to topicals + antihistamine; never as first line)
- Reconsider diagnosis after 12 weeks (persistent eruption > 12 wk  > biopsy + drug review + repeat RPR — mycosis fungoides, pityriasis lichenoides chronica, persistent atypical PR, and drug induced eruption are the differential)

Monitoring

Regimen monitoring:
- follow-up review at 4-6 weeks to confirm expected resolution trajectory (Drago JAAD 2009 PMID 19615540)
- post-inflammatory pigmentary change is expected and benign in darker skin — explicit counselling at every visit
- pregnant patients: OB continuity throughout the eruption and through delivery (Drago JAAD 2008 PMID 18489054)
- topical steroid duration + BSA monitoring to avoid atrophy
- persistence > 12 wk or recurrence -> repeat RPR + drug review + consider biopsy

Setting (outpatient) monitoring:
- Review at 4-6 weeks to confirm expected resolution; persistence > 12 wk triggers re-workup (Mashoudy PMID 39798062)
- Topical steroid duration + BSA limit to prevent atrophy
- Pregnancy OB continuity throughout

Follow-up plan: Confirm resolution by 8-12 weeks. PERSISTENT (>12 weeks) or RECURRENT eruption -> re-evaluate: repeat RPR, drug review, biopsy for pityriasis lichenoides chronica / drug-induced eruption / mycosis fungoides. Counsel that recurrence is uncommon (~3%) but can happen; post-inflammatory pigmentary changes may persist for months and are not a sign of treatment failure; pregnant patients with first-trimester PR need OB continuity through delivery.
- Close-out criterion: resolution confirmed; persistence triggers re-workup; pregnancy continuity arranged

Monitoring phase: Review at 4-6 weeks to confirm expected resolution and absence of complications (post-inflammatory pigment change is expected and benign in darker skin). For pregnant patients: OB co-management throughout pregnancy with PR. For patients started on topical steroid: limit course (~1-2 weeks at a time on body; shorter on face/folds) to avoid atrophy. For patients on oral antihistamine: monitor sedation effects and avoid driving with hydroxyzine.

Disposition

Current setting: outpatient — Confirm PR clinically, actively rule out secondary syphilis in any atypical / palm-sole / sexually-active / pregnant / persistent case, reassure that PR is self-limited (6-8 wk), provide symptomatic relief proportional to itch + QoL impact, and reserve antivirals/phototherapy for severe disease (Drago JAAD 2009 PMID 19615540; Mashoudy 2025 PMID 39798062; Ciccarese 2024 PMID 39597810; Drago JAAD 2008 PMID 18489054)

Disposition criteria:
- Classic PR confirmed clinically + low STI risk -> reassurance + symptomatic care + 4-6 week follow-up
- Atypical or sexually-active or palm/sole -> RPR + treponemal + ddx workup + selective derm referral
- Pregnant patient -> OB co-management throughout
- Persistent / recurrent / treatment-resistant -> derm referral for biopsy + extended workup

Escalation triggers (move to higher acuity):
- Palm/sole/mucosa involvement OR generalised lymphadenopathy -> urgent RPR + treponemal serology to exclude secondary syphilis
- Pregnancy with first-trimester onset -> OB referral (Drago PMID 18489054)
- Persistent (>12 wk) or atypical / fixed / poikilodermatous lesions -> skin biopsy for mycosis fungoides + pityriasis lichenoides chronica
- Recent drug or vaccine link with atypical histology -> derm.drug-eruption.core.v1 review

Earlier-Return Triggers

Return-precaution thresholds (watch for):
- [SEVERE] PR-like eruption with palm or sole involvement, mucous patches, condyloma lata, generalised lymphadenopathy, or any sexually-active patient with STI risk (Drago JAAD 2009 PMID 19615540)
- [SEVERE] PR developing in the first 15 gestational weeks (Drago JAAD 2008 PMID 18489054)
- [MODERATE] PR-like eruption persisting > 12 weeks, with atypical / fixed / poikilodermatous morphology, or recurrence (Mashoudy 2025 PMID 39798062)

Citations

- Drago JAAD 2009 critical-appraisal review (PMID 19615540, DOI 10.1016/j.jaad.2008.07.045) + Mashoudy Am J Clin Dermatol 2025 review (PMID 39798062, DOI 10.1007/s40257-024-00915-7) + Ciccarese J Clin Med 2024 network meta-analysis (PMID 39597810, DOI 10.3390/jcm13226666) + Drago JAAD 2008 pregnancy outcome (PMID 18489054, DOI 10.1016/j.jaad.2007.05.030) + Durgin J Cutan Pathol 2024 pityriasiform drug eruption (PMID 39021288, DOI 10.1111/cup.14692) [PMID:19615540](https://pubmed.ncbi.nlm.nih.gov/19615540/)
- Cited evidence (PMID 39798062) [PMID:39798062](https://pubmed.ncbi.nlm.nih.gov/39798062/)
- Cited evidence (PMID 39597810) [PMID:39597810](https://pubmed.ncbi.nlm.nih.gov/39597810/)
- Cited evidence (PMID 18489054) [PMID:18489054](https://pubmed.ncbi.nlm.nih.gov/18489054/)
- Cited evidence (PMID 39021288) [PMID:39021288](https://pubmed.ncbi.nlm.nih.gov/39021288/)

Last reconciled with current guidelines: 2026-05-26.
References
  • Drago JAAD 2009 critical-appraisal review (PMID 19615540, DOI 10.1016/j.jaad.2008.07.045) + Mashoudy Am J Clin Dermatol 2025 review (PMID 39798062, DOI 10.1007/s40257-024-00915-7) + Ciccarese J Clin Med 2024 network meta-analysis (PMID 39597810, DOI 10.3390/jcm13226666) + Drago JAAD 2008 pregnancy outcome (PMID 18489054, DOI 10.1016/j.jaad.2007.05.030) + Durgin J Cutan Pathol 2024 pityriasiform drug eruption (PMID 39021288, DOI 10.1111/cup.14692) — PMID:19615540
  • Cited evidence (PMID 39798062) — PMID:39798062
  • Cited evidence (PMID 39597810) — PMID:39597810
  • Cited evidence (PMID 18489054) — PMID:18489054
  • Cited evidence (PMID 39021288) — PMID:39021288