derm.contact-dermatitis.core.v1PRODUCTION

derm.contact-dermatitis.core.v1

Contact dermatitis — allergic vs irritant (dermatology lens)

dermatologysubacutechronicadultpediatric

Hard-required inputs

0 / 11

Care setting:

Encounter flow

12/12 authored

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

Current phase

Frame

Detailed

Frame as an EXPOSURE-DRIVEN eczematous disease where allergen/irritant identification + avoidance is the definitive treatment and topical/systemic therapy is symptom control while avoidance takes effect. Separate ICD (innate, dose-dependent, burning≈itch, sharp contact-site margins, no sensitisation) from ACD (delayed type-IV, requires prior sensitisation, intense itch, may spread beyond site, id-reaction). Patch testing is the key ACD tool. Severe acute (rhus periorbital/airway), erythroderma, and occupational-disabling presentations are recognised here and escalated/routed.

Inputs

Actions

Advance rule

Set

Advance when

contact framing set; ICD-vs-ACD axis + avoidance-as-definitive-treatment + escape routes noted

Patient inputs (17)

itch_vs_burning_quality*symptom • CONTEXT

Itch-dominant favours ACD (delayed-type IV); burning/stinging ≈ itch confined to site favours ICD (innate) (Fyhrquist-Vanni Dermatol Clin 2007 PMID 17903620)

spread_beyond_contact_site*symptom • CONTEXT

Spread beyond the contact site / id (autoeczematisation) reaction strongly favours ACD over ICD and raises the patch-test prior (Nosbaum Eur J Dermatol 2009 PMID 19447733)

prior_sensitisation_or_re_exposure*history • CONTEXT

not present

ACD requires prior sensitisation and occurs on re-exposure (delayed type-IV); ICD occurs dose-dependently without sensitisation in anyone sufficiently exposed (Nosbaum Eur J Dermatol 2009 PMID 19447733)

occupational_exposure_inventory*history • CONTEXT

not present

Occupation/hobby exposure map (wet work, gloves, hair chemicals, metals, resins, biocides) drives the supplemental patch-test series + return-to-work plan (Karagounis Curr Allergy Asthma Rep 2023 PMID 36749448)

personal_product_and_medicament_inventory*history • CONTEXT

not present

Cosmetics/fragrance, preservatives, topical antibiotics/corticosteroids, rubber/leather, jewellery — the personal allergen map; topical medicament ACD is commonly missed (NACDG 2021-2022 PMID 40274377)

atopic_diathesis*history • CONTEXT

not present

Atopy impairs the barrier (↑ ICD and ACD susceptibility) and ACD is frequently superimposed on atopic dermatitis — low patch-test threshold in recalcitrant AD (route derm.atopic-dermatitis.core.v1) (Karagounis 2023 PMID 36749448)

lesion_distribution_and_margin*symptom • ENTRY

Exposure-mapped geometric/linear margins anchor the contact diagnosis and the ICD-vs-ACD-vs-endogenous-eczema split (Nosbaum Eur J Dermatol 2009 PMID 19447733)

secondary_infection_signs*symptom • RED_FLAGS

Weeping/honey-crust/pustules over excoriated dermatitis → S. aureus secondary infection requiring anti-staphylococcal therapy before/with anti-inflammatory escalation (Karagounis 2023 PMID 36749448)

periorbital_or_airway_oedema*symptom • RED_FLAGS

Facial/periorbital oedema or airway involvement in severe acute ACD (e.g. rhus) → systemic corticosteroid + ED (Curtis J Clin Med Res 2014 PMID 25247016)

erythroderma_extent*symptom • RED_FLAGS

>90% BSA confluent erythema from contact dermatitis (e.g. airborne/systemic contact dermatitis) — thermoregulatory/fluid risk + admission threshold

age*demographic • TREATMENT

Pediatric allergens (nickel, shin-guard/soccer ICD, diaper ICD), pediatric topical-potency limits, and systemic-agent age cut-offs gate the ladder

photodistribution_patternsymptom • BRANCHING_WORKUP

Sun-exposed-site accentuation with sparing of shaded areas suggests photoallergic/phototoxic contact dermatitis → photopatch testing branch (Nosbaum Eur J Dermatol 2009 PMID 19447733)

patch_test_concurrent_active_dermatitishistory • BRANCHING_WORKUP

not present

Active dermatitis on the back / recent systemic steroids / recent UV → "angry back" false-positives + false-negatives; patch-test validity is conditional on test conditions (ACDS 2020 PMID 32947457)

cbc_with_differentiallab • INITIAL_WORKUP

Baseline + monitoring for steroid-sparing systemics (cyclosporine/methotrexate/azathioprine) in chronic refractory ACD

lftlab • INITIAL_WORKUP

Methotrexate / cyclosporine / azathioprine baseline + on-treatment hepatotoxicity monitoring in the chronic ladder

pregnancy_lactationhistory • TREATMENT

not present

Systemic retinoid (alitretinoin) / methotrexate / mycophenolate contraindicated in pregnancy; gates the chronic systemic ladder

creatininelab • TREATMENT

Cyclosporine nephrotoxicity surveillance + race-free CKD-EPI 2021 eGFR for systemic-agent dosing

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

Severity triggers (7)

7 need judgement

informationallife_threateningsevere_acute_widespread_acd_airway
Severe acute widespread vesicobullous ACD (e.g. rhus/poison-ivy) with facial/periorbital oedema or airway involvement
Trigger could not be auto-evaluated — needs clinician judgement.
informationalseverecontact_dermatitis_erythroderma
>90% BSA confluent erythema from contact dermatitis (airborne / systemic contact dermatitis) with thermoregulatory or fluid compromise
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderatesecondary_infection_excoriated_dermatitis
Honey-coloured crust, pustules, weeping, rapid worsening — S. aureus secondary infection of excoriated contact dermatitis
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderateoccupational_disabling_hand_dermatitis
Occupational hand dermatitis causing work disability (wet work, hairdressers, healthcare, construction/metalwork)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderaterecalcitrant_dermatitis_patch_test_trigger
Eczema (incl. atopic) recalcitrant to adequate therapy or atypically distributed — suspect superimposed/unrecognised ACD
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmildinadequate_steroid_taper_rhus_pitfall
Severe rhus/poison-ivy ACD prescribed a <14 d steroid burst (5-day course / Medrol dose-pak)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmildcorticosteroid_contact_allergy_perpetuator
Contact dermatitis that worsens or fails to clear on topical corticosteroids — suspected corticosteroid contact allergy
Trigger could not be auto-evaluated — needs clinician judgement.

Workflow calculators

Run this disease's risk and dosing calculators inline.

TREATMENToptionalDrives dose adjustment

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Recommended regimen

Contact dermatitis — trigger-elimination-first + stepwise anti-inflammatory ladder (ACD/ICD)

axis: contact_dermatitis_avoidance_first_ladderstep 1 - Step 1 — Identify + ELIMINATE the trigger (definitive treatment; every patient, every step)

Selected step "Step 1 — Identify + ELIMINATE the trigger (definitive treatment; every patient, every step)" — All contact dermatitis, continuously — allergen/irritant avoidance is the definitive treatment; topical/systemic therapy only controls symptoms while avoidance takes effect

allergen_irritant_identification_and_strict_avoidance
first line
decision_gate
triggers: acd_relevant_allergen_identified, icd_irritant_exposure_identified
Nosbaum Eur J Dermatol 2009 (PMID 19447733) / ACDS 2020 (PMID 32947457) — identification (patch test for ACD; exposure history for ICD) + strict avoidance of the allergen, cross-reactors, and concomitant irritants is the only definitive cure; supply a named safe-product / Contact Allergen Management Program list.
barrier_protection_gloves_and_substitution
first line
barrier_repair
triggers: wet_work, occupational_exposure, hand_dermatitis
Karagounis Curr Allergy Asthma Rep 2023 (PMID 36749448) — gloves (allergen-appropriate; cotton liners), reduced wet-work, workplace substitution/ergonomics; glove rubber-accelerator allergy itself can perpetuate hand dermatitis.
emollient_barrier_repair
first line
barrier_repair
triggers: icd, impaired_barrier, all_severities
Karagounis 2023 (PMID 36749448) — liberal emollients restore the barrier and are the mainstay of ICD; reduce irritant penetration and accelerate resolution once exposure is removed.

outpatient playbook — drug actions (4)

1. allergen/irritant identification + strict avoidance + barrier protection + emollient (definitive)
n/a • n/a • continuous, indefinitely
trigger: All contact dermatitis — the only curative step (Nosbaum 2009 PMID 19447733)
Patch test for ACD / exposure history for ICD → named safe-product list, cross-reactor avoidance, gloves/substitution
2. triamcinolone 0.1% (trunk/extremity) / hydrocortisone or tacrolimus (face/eyelid/folds)
rxcui 10759
0.1% / 2.5% / 0.1% • topical • BID then taper
trigger: Active localised/mild–moderate inflammation (Nosbaum 2009 PMID 19447733)
Symptom control while avoidance takes effect; TCI where corticosteroid contact allergy suspected
3. clobetasol 0.05% short burst (thick hand/foot/lichenified)
rxcui 21245
0.05% • topical • BID ≤2 wk then step down
trigger: Thick lichenified palmoplantar contact dermatitis (Karagounis 2023 PMID 36749448)
Thick palmoplantar skin requires superpotent topical; limited duration
4. prednisone (severe acute widespread ACD, e.g. rhus) — ≥2–3 wk taper
rxcui 8640
0.5–1 mg/kg/day • PO • daily, tapered ≥14 d
trigger: Severe acute widespread ACD without periorbital/airway oedema (Curtis & Lewis 2014 PMID 25247016)
Adequate taper prevents rebound; short bursts under-treat severe rhus

Auto-drafted A&P note

outpatient

Subjective

- Possible entry pathways: Subacute/chronic eczematous rash whose distribution maps to a contact exposure (geometric/linear margins, hands, face/eyelid, feet) (Nosbaum Eur J Dermatol 2009 PMID 19447733); Temporal/spatial link to an occupational or personal-product exposure (wet work, gloves, cosmetics, jewellery, topical medicaments) (Karagounis Curr Allergy Asthma Rep 2023 PMID 36749448); Itch-dominant + spread beyond contact site (favours ACD) vs burning/stinging confined to contact site (favours ICD) (Fyhrquist-Vanni Dermatol Clin 2007 PMID 17903620).

Objective

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

Assessment

**Contact dermatitis — allergic vs irritant (dermatology lens)** (derm.contact-dermatitis.core.v1).
Phenotype framing: Terminal contact-dermatitis differential with named pivots: ACD vs ICD (sensitisation history + spread-beyond-contact + patch-test pivot) vs atopic dermatitis (flexural + atopy + childhood onset pivot — route derm.atopic-dermatitis.core.v1; ACD frequently superimposed) vs nummular eczema (discrete coin lesions pivot) vs seborrheic dermatitis (greasy scale scalp/nasolabial pivot) vs psoriasis (sharp salmon plaque + silver scale + nail pits pivot — route derm.psoriasis.core.v1) vs tinea (KOH-positive annular advancing scale pivot) vs cellulitis (acute red-hot tender, portal + pain>itch pivot — route derm.cellulitis.core.v1) vs photoallergic/phototoxic contact dermatitis (photodistribution + photopatch pivot) vs systemic contact dermatitis (ingested/systemic exposure to a contact allergen, baboon syndrome/SDRIFE pivot).
Scope: Frame as an EXPOSURE-DRIVEN eczematous disease where allergen/irritant identification + avoidance is the definitive treatment and topical/systemic therapy is symptom control while avoidance takes effect. Separate ICD (innate, dose-dependent, burning≈itch, sharp contact-site margins, no sensitisation) from ACD (delayed type-IV, requires prior sensitisation, intense itch, may spread beyond site, id-reaction). Patch testing is the key ACD tool. Severe acute (rhus periorbital/airway), erythroderma, and occupational-disabling presentations are recognised here and escalated/routed.

No severity triggers fired against current inputs.

Plan

Regimen axis: **Contact dermatitis — trigger-elimination-first + stepwise anti-inflammatory ladder (ACD/ICD)** — step "Step 1 — Identify + ELIMINATE the trigger (definitive treatment; every patient, every step)".
1. allergen_irritant_identification_and_strict_avoidance (decision_gate, first line) — Nosbaum Eur J Dermatol 2009 (PMID 19447733) / ACDS 2020 (PMID 32947457) — identification (patch test for ACD; exposure history for ICD) + strict avoidance of the allergen, cross-reactors, and concomitant irritants is the only definitive cure; supply a named safe-product / Contact Allergen Management Program list.
2. barrier_protection_gloves_and_substitution (barrier_repair, first line) — Karagounis Curr Allergy Asthma Rep 2023 (PMID 36749448) — gloves (allergen-appropriate; cotton liners), reduced wet-work, workplace substitution/ergonomics; glove rubber-accelerator allergy itself can perpetuate hand dermatitis.
3. emollient_barrier_repair (barrier_repair, first line) — Karagounis 2023 (PMID 36749448) — liberal emollients restore the barrier and are the mainstay of ICD; reduce irritant penetration and accelerate resolution once exposure is removed.

Setting playbook (outpatient) — Separate ACD from ICD (and from endogenous/superimposed eczema), perform/refer patch testing with ICDRG grading + relevance assignment, build a named allergen/irritant avoidance + barrier plan as the definitive treatment, and run the topical → phototherapy → systemic ladder for symptom control (Nosbaum Eur J Dermatol 2009 PMID 19447733; ACDS 2020 PMID 32947457; Karagounis 2023 PMID 36749448)
4. allergen/irritant identification + strict avoidance + barrier protection + emollient (definitive) n/a n/a continuous, indefinitely — All contact dermatitis — the only curative step (Nosbaum 2009 PMID 19447733) (Patch test for ACD / exposure history for ICD → named safe-product list, cross-reactor avoidance, gloves/substitution)
5. triamcinolone 0.1% (trunk/extremity) / hydrocortisone or tacrolimus (face/eyelid/folds) 0.1% / 2.5% / 0.1% topical BID then taper — Active localised/mild–moderate inflammation (Nosbaum 2009 PMID 19447733) (Symptom control while avoidance takes effect; TCI where corticosteroid contact allergy suspected)
6. clobetasol 0.05% short burst (thick hand/foot/lichenified) 0.05% topical BID ≤2 wk then step down — Thick lichenified palmoplantar contact dermatitis (Karagounis 2023 PMID 36749448) (Thick palmoplantar skin requires superpotent topical; limited duration)
7. prednisone (severe acute widespread ACD, e.g. rhus) — ≥2–3 wk taper 0.5–1 mg/kg/day PO daily, tapered ≥14 d — Severe acute widespread ACD without periorbital/airway oedema (Curtis & Lewis 2014 PMID 25247016) (Adequate taper prevents rebound; short bursts under-treat severe rhus)

Non-pharmacologic actions:
- Written named-allergen avoidance plan + cross-reactor + safe-product (Contact Allergen Management Program) list (ACDS 2020 PMID 32947457)
- Occupational substitution / glove + barrier-cream / wet-work reduction plan; return-to-work + workers-comp documentation (Karagounis 2023 PMID 36749448)
- Patch-test referral if recalcitrant / occupational / superimposed-on-another-dermatosis (ACDS 2020 PMID 32947457)
- nbUVB / hand-PUVA referral for chronic recalcitrant hand dermatitis deferring systemics (Karagounis 2023 PMID 36749448)

AVOID / contraindication checks:
- Identification and avoidance is definitive treatment (Nosbaum Eur J Dermatol 2009 PMID 19447733 — pharmacotherapy is symptom control only; the cure is removing the allergen/irritant + cross reactors)
- Against inadequate short steroid taper for severe rhus acd (Curtis & Lewis 2014 PMID 25247016 — <14 d bursts cause rebound; use ≥2–3 wk taper)
- Topical corticosteroid contact allergy can perpetuate dermatitis (ACDS 2020 PMID 32947457 — tixocortol 21 pivalate / budesonide screening markers; switch to a topical calcineurin inhibitor)
- Alitretinoin methotrexate mycophenolate contraindicated in pregnancy (strictly teratogenic — pregnancy prevention programme for alitretinoin)
- Cyclosporine nephrotoxicity hypertension limit to short term (≤1 y; monitor BP + creatinine via calc.ckd_epi_2021)
- Patch test validity conditional (ACDS 2020 PMID 32947457 — defer if active back dermatitis / recent systemic corticosteroids / recent UV: false negatives + "angry back" false positives)

Monitoring

Regimen monitoring:
- patch test read Day2 AND Day4-7 then relevance assignment (ACDS 2020 PMID 32947457 — Day-2-only misses ~30% of relevant reactions)
- clinical response to avoidance plus ladder at 4-12wk avoidance benefit accrues over weeks-months (Nosbaum 2009 PMID 19447733)
- severe acute ACD steroid course completion and rebound watch (Curtis & Lewis 2014 PMID 25247016)
- cyclosporine: BP + creatinine q2wk during titration
- methotrexate/azathioprine: CBC + LFT periodic (TPMT before azathioprine)
- dupilumab: conjunctivitis surveillance — no routine labs (Slodownik 2022 PMID 35462358)

Setting (outpatient) monitoring:
- Patch-test read Day-2 + Day-4(-7) then assign relevance (current/past/unknown) (ACDS 2020 PMID 32947457)
- Clinical response to avoidance + ladder at 4-12 wk; persistent dermatitis despite strict avoidance → unidentified allergen / ICD / endogenous / corticosteroid contact allergy (Nosbaum 2009 PMID 19447733)
- Steroid-sparing systemic safety labs on schedule (cyclosporine BP/Cr; MTX/AZA CBC/LFT)

Follow-up plan: Chronic-disease maintenance: written allergen/irritant avoidance plan with named allergens + cross-reactors + safe-product list (Contact Allergen Management Program / safe-list), barrier-protection + emollient habit, occupational return-to-work + workplace-substitution plan and workers-comp documentation where applicable, education on delayed re-exposure flares and id reactions, and re-patch-test criteria if a new pattern emerges. Dermatology continuity for any systemic agent; reassess for superimposed ACD if a sibling-engine dermatosis remains recalcitrant.
- Close-out criterion: avoidance + safe-product + barrier + occupational/return-to-work plan documented; re-test + sibling-recalcitrance criteria set

Monitoring phase: Disease: re-assess at the patch-test reading schedule (Day-2 + Day-4(-7)) then clinically at 4-12 wk to judge response to avoidance + ladder step (avoidance benefit accrues over weeks-months; persistent dermatitis despite documented strict avoidance argues an unidentified allergen, ICD, an endogenous dermatosis, or corticosteroid contact allergy). Drug safety: short systemic steroid course completion + rebound watch; steroid-sparing systemics — cyclosporine BP + creatinine (calc.ckd_epi_2021) q2wk during titration; methotrexate/azathioprine CBC + LFT; dupilumab conjunctivitis surveillance (no routine labs).

Disposition

Current setting: outpatient — Separate ACD from ICD (and from endogenous/superimposed eczema), perform/refer patch testing with ICDRG grading + relevance assignment, build a named allergen/irritant avoidance + barrier plan as the definitive treatment, and run the topical → phototherapy → systemic ladder for symptom control (Nosbaum Eur J Dermatol 2009 PMID 19447733; ACDS 2020 PMID 32947457; Karagounis 2023 PMID 36749448)

Disposition criteria:
- Continue avoidance + ladder + derm follow-up if responding (Nosbaum 2009 PMID 19447733)
- Step up the ladder only after re-verifying avoidance adequacy + considering unidentified allergen / corticosteroid contact allergy
- Refer occupational disabling disease to occupational medicine; admit only for severe acute/erythroderma/failed-infection criteria

Escalation triggers (move to higher acuity):
- Severe acute widespread ACD with facial/periorbital oedema or airway involvement → ED + systemic corticosteroid (Curtis & Lewis 2014 PMID 25247016)
- Contact-dermatitis erythroderma with thermoregulatory/fluid compromise → admit
- Occupational disabling hand dermatitis → occupational-medicine + return-to-work referral; patch test (Karagounis 2023 PMID 36749448)

Earlier-Return Triggers

Return-precaution thresholds (watch for):
- [LIFE_THREATENING] Severe acute widespread vesicobullous ACD (e.g. rhus/poison-ivy) with facial/periorbital oedema or airway involvement
- [SEVERE] >90% BSA confluent erythema from contact dermatitis (airborne / systemic contact dermatitis) with thermoregulatory or fluid compromise
- [MODERATE] Honey-coloured crust, pustules, weeping, rapid worsening — S. aureus secondary infection of excoriated contact dermatitis

Citations

- ACDS Core Allergen Series 2020 Update (Schalock et al, Dermatitis; PMID 32947457, with 2017 PMID 28169850 + original PMID 23340393) + NACDG Patch Test Results 2021-2022 (Houle/DeKoven et al, Dermatitis; PMID 40274377 — current North American allergen-prevalence + relevance reference) + Occupational Hand Dermatitis review (Karagounis & Cohen, Curr Allergy Asthma Rep 2023; PMID 36749448) + ICD-vs-ACD pathophysiology (Nosbaum et al, Eur J Dermatol 2009 PMID 19447733; Fyhrquist-Vanni et al, Dermatol Clin 2007 PMID 17903620) + poison-ivy systemic-steroid duration RCT (Curtis & Lewis, J Clin Med Res 2014 PMID 25247016) + dupilumab for refractory/occupational ACD (Slodownik et al, Dermatology 2022 PMID 35462358; Goldminz & Scheinman, Dermatol Ther 2018 PMID 30246906) [PMID:40274377](https://pubmed.ncbi.nlm.nih.gov/40274377/)
- Cited evidence (PMID 32947457) [PMID:32947457](https://pubmed.ncbi.nlm.nih.gov/32947457/)
- Cited evidence (PMID 28169850) [PMID:28169850](https://pubmed.ncbi.nlm.nih.gov/28169850/)
- Cited evidence (PMID 23340393) [PMID:23340393](https://pubmed.ncbi.nlm.nih.gov/23340393/)
- Cited evidence (PMID 36749448) [PMID:36749448](https://pubmed.ncbi.nlm.nih.gov/36749448/)

Last reconciled with current guidelines: 2026-05-22.

References

ACDS Core Allergen Series 2020 Update (Schalock et al, Dermatitis; PMID 32947457, with 2017 PMID 28169850 + original PMID 23340393) + NACDG Patch Test Results 2021-2022 (Houle/DeKoven et al, Dermatitis; PMID 40274377 — current North American allergen-prevalence + relevance reference) + Occupational Hand Dermatitis review (Karagounis & Cohen, Curr Allergy Asthma Rep 2023; PMID 36749448) + ICD-vs-ACD pathophysiology (Nosbaum et al, Eur J Dermatol 2009 PMID 19447733; Fyhrquist-Vanni et al, Dermatol Clin 2007 PMID 17903620) + poison-ivy systemic-steroid duration RCT (Curtis & Lewis, J Clin Med Res 2014 PMID 25247016) + dupilumab for refractory/occupational ACD (Slodownik et al, Dermatology 2022 PMID 35462358; Goldminz & Scheinman, Dermatol Ther 2018 PMID 30246906) — PMID:40274377
Cited evidence (PMID 32947457) — PMID:32947457
Cited evidence (PMID 28169850) — PMID:28169850
Cited evidence (PMID 23340393) — PMID:23340393
Cited evidence (PMID 36749448) — PMID:36749448