12-phase flow (12)

1. 1FRAME
   Frame as a CHRONIC pilosebaceous inflammatory disease driven by four pathogenic factors (follicular hyperkeratinisation, C. acnes, sebum/androgen, inflammation), managed on a stepwise multi-mechanism ladder — NOT a transient cosmetic rash. Scarring, dyspigmentation, and psychosocial burden are tracked as disease outcomes. Acneiform mimics + acne fulminans are recognised here and routed/escalated.
   advance: chronic acne framing set; acneiform-mimic + fulminans escape routes noted
2. 2ENTRY
   Recognise the chronic comedonal/papulopustular eruption vs the nodulocystic/scarring, sudden-adult-female, drug-acneiform, or acute-ulcerative (fulminans) entries; capture lesion morphology up front (it sets the ladder entry point).
   inputs: lesion_morphology_taxonomy
   actions: workup.chronic_pruritus
   advance: entry trigger present; lesion morphology recorded
3. 3CONTEXT
   Build context: full lesion taxonomy + distribution, psychosocial/QoL/suicidality burden, acneiform-drug exposure (steroid/EGFR-i/lithium/androgen), prolonged-oral-antibiotic history (resistance + gram-negative-folliculitis), and a rigorous prior-therapy-adequacy assessment (agent × ≥8-12 wk × adherence — under-treatment is the commonest "failure").
   inputs: psychosocial_qol_burden, acneiform_drug_exposure, prior_acne_therapy_adequacy, prolonged_oral_antibiotic_history
   actions: workup.chronic_pruritus
   advance: morphology + burden + drug/antibiotic context + true-adequacy established
4. 4RED_FLAGS
   Acne fulminans (acute ulcerative/crusted nodular acne + fever/malaise/arthralgia ± osteolytic lesions) → systemic corticosteroid bridge then low-dose isotretinoin, NOT antibiotic-first or abrupt high-dose isotretinoin (can precipitate fulminans). Suicidality / severe psychosocial crisis → mental-health safety net. Gram-negative folliculitis after prolonged oral antibiotics. These are recognised + escalated here.
   inputs: psychosocial_qol_burden
   actions: panel.cbc
   advance: fulminans / suicidality / gram-negative-folliculitis screened and escalated if present
5. 5INITIAL_WORKUP
   Acne is a clinical diagnosis — no test confirms it. Targeted workup: pregnancy test before isotretinoin/hormonal/tetracycline in reproductive-potential patients; baseline lipids/LFT if isotretinoin planned; CBC if fulminans; androgen panel deferred to BRANCHING when hyperandrogenism signs present. Routine microbiologic/endocrine testing is NOT required to diagnose typical acne (AAD 2024 PMID 38300170).
   inputs: pregnancy_test
   actions: panel.cbc, panel.lft, panel.hormone
   advance: pre-systemic safety/pregnancy testing drawn if escalation likely; routine testing deferred otherwise
6. 6BRANCHING_WORKUP
   Endocrine branch: hyperandrogenism signs (hirsutism, irregular menses, virilisation, alopecia) OR sudden severe/recalcitrant adult-female acne → total/free testosterone + DHEAS + 17-OHP + LH/FSH (panel.hormone); markedly elevated androgens / rapid virilisation → urgent tumour evaluation. Drug branch: temporal acneiform-drug link → route derm.drug-eruption.core.v1. Otherwise typical acne confirmed clinically.
   inputs: hyperandrogenism_signs, androgen_panel
   actions: panel.hormone
   advance: endocrine workup sent if indicated OR typical acne confirmed; drug-acneiform routed if present
7. 7DIFFERENTIAL
   Terminal acneiform differential with named pivots: acne vulgaris (comedones + mixed lesions) vs rosacea (NO comedones + flushing/telangiectasia/persistent centrofacial erythema — route derm.rosacea.core.v1) vs folliculitis (gram-negative / Malassezia / pseudomonal — monomorphic follicular pustules) vs perioral dermatitis (perioral/periocular sparing vermilion, micropapules) vs hidradenitis suppurativa (intertriginous nodules/sinus tracts/double comedones — route derm.hidradenitis-suppurativa.core.v1) vs drug-induced acneiform (monomorphic, comedone-poor, drug timeline — route derm.drug-eruption.core.v1) vs acne fulminans / SAPHO vs endocrine hyperandrogenism (PCOS/CAH/tumour driver).
   inputs: rosacea_vs_acne_features, intertriginous_nodules_sinus_tracts
   advance: single best diagnosis selected; mimic routed by engine_id; endocrine driver flagged if present
8. 8RISK_STRATIFICATION
   Severity = lesion count × type × extent × scarring × dyspigmentation × psychosocial burden (IGA / Leeds / GAGS where used — schema-blocked as TS calculators, captured narratively). Mild comedonal → topical retinoid + BPO; mild-moderate inflammatory → +topical antibiotic (with BPO)/fixed-combo/clascoterone/azelaic; moderate-severe → +oral antibiotic and/or hormonal; severe nodulocystic / scarring / recalcitrant / high psychosocial burden / fulminans → isotretinoin (with the steroid bridge if fulminans).
   inputs: acne_severity_grade, scarring_or_dyspigmentation
   advance: mild/moderate/severe tier + scarring/psychosocial overlay + ladder-step decision assigned
9. 9TREATMENT
   Stepwise AAD 2024 ladder: Step 1 topical retinoid (tretinoin/adapalene/tazarotene/trifarotene) + BPO; Step 2 +topical antibiotic (clindamycin ALWAYS with BPO — resistance), fixed combinations, clascoterone (androgen-receptor), azelaic acid; Step 3 +oral antibiotic (doxycycline/minocycline/sarecycline) time-limited ~3-4 mo, NEVER monotherapy, ALWAYS with topical retinoid+BPO, NEVER with a topical antibiotic, and/or hormonal therapy (COC, spironolactone for adult females); Step 4 oral isotretinoin (cumulative dose, iPLEDGE REMS, absolute pregnancy contraindication, lipid/LFT + mood monitoring) for severe nodulocystic/scarring/recalcitrant; acne fulminans → systemic corticosteroid bridge then low-dose isotretinoin. Adjuncts: intralesional corticosteroid for large nodules, scar-management referral. Comorbidity gating: pregnancy avoids isotretinoin/tetracyclines/spironolactone/COC; <8 y avoids tetracyclines; isotretinoin+tetracycline avoided (pseudotumor cerebri).
   inputs: pregnancy_lactation, age, reproductive_potential_contraception
   advance: appropriate ladder step started; antibiotic-stewardship + isotretinoin-REMS + pregnancy gating enforced
10. 10DISPOSITION
    Almost entirely outpatient/derm-clinic. Acne fulminans with systemic features or osteoarticular involvement may warrant urgent specialist/inpatient input. Suicidality crisis → mental-health pathway. Isotretinoin initiated and monitored under iPLEDGE via dermatology; endocrine-driver and acneiform-mimic cases routed OUT by engine_id.
    inputs: psychosocial_qol_burden
    advance: disposition documented; specialist/MH routing for fulminans/suicidality; derm follow-up arranged
11. 11MONITORING
    Disease: reassess response at 8-12 wk per step (topicals/oral antibiotics: lesion-count + IGA; isotretinoin: cumulative dose progress to target). Drug safety: isotretinoin → pregnancy test monthly (iPLEDGE) + lipids/LFT (AAD 2024 supports infrequent monitoring for most low-risk patients) + mood/depression screen at each visit; spironolactone → routine serum-potassium monitoring NOT required in healthy young women (encode this nuance — reserve K for renal/cardiac/RAAS-drug/older patients); oral antibiotics → cap duration ~3-4 mo, reassess, ensure concomitant BPO. Re-evaluate diagnosis (endocrine, gram-negative folliculitis, mimic) if no response.
    inputs: lipid_panel_lft
    actions: panel.lft, panel.renal
    advance: objective response assessed at 8-12 wk; isotretinoin REMS + safety labs + mood screen on schedule; antibiotic duration capped
12. 12FOLLOWUP
    Chronic-disease maintenance: topical-retinoid maintenance after oral therapy stops (relapse prevention, the single most effective maintenance strategy), adherence/expectation counselling (response takes 8-12 wk; no antibiotic monotherapy/long courses), scar + dyspigmentation management and referral, mental-health surveillance, hormonal-therapy continuity for adult females, and isotretinoin post-course relapse monitoring (a second course may be needed). Skin-of-colour: PIH-directed gentle regimens minimising irritation.
    inputs: prior_acne_therapy_adequacy, psychosocial_qol_burden
    actions: workup.chronic_pruritus
    advance: maintenance retinoid + adherence/expectation + scar/dyspigmentation + MH surveillance documented