Autosomal recessive congenital ichthyosis 4B (ARCI-4B) clinically, ARCI-4B corresponds to Harlequin ichthyosis, a life-threatening neonatal form of ichthyosis caused by loss-of-function variants in the ABCA12 lipid transporter. Babies are born with very thick, plate-like skin separated by deep fissures, ectropion (out-turned eyelids), eclabium (everted lips), limb tightness/contractures, and a highly impaired skin barrier that drives dehydration, infection, and temperature/energy loss. Survival has improved with modern neonatal intensive care and early oral retinoids. Long-term care is supportive and preventive; no curative therapy exists yet. PMC+3NCBI+3preventiongenetics.com+3

ARCI-4B is a genetic skin disease present at birth. A baby’s outer skin grows too thick and hard. This skin forms large plates with deep cracks. The eyelids can turn out, the lips can pull open, and the chest and limbs can be tight. Because the skin barrier is weak, the body loses water, heat, and energy, and germs can enter easily. The gene problem is in ABCA12, which normally moves special fats into the skin’s outer layers. Without these fats, the protective skin barrier does not build correctly. With careful care in the newborn period (hydration, warmth, infection control, eye care) and early retinoid therapy, many children can now survive. Later in life, scaling and dryness continue and need daily skin care. There is no cure yet, but research into gene and cell therapies is ongoing. MDPI+3preventiongenetics.com+3JAMA Network+3

Autosomal Recessive Congenital Ichthyosis 4B (ARCI-4B) is a rare, inherited skin condition. Babies are usually born with tight, shiny skin (often called a collodion membrane) that later peels and turns into dry, thick, scaly skin over most of the body. The skin may look red at first. The main reason is a change (mutation) in a skin-lipid enzyme gene called ALOX12B. This gene helps make lipids (oils) that glue skin cells together and keep water in the body. When ALOX12B does not work, the skin barrier is weak. Water escapes, the skin dries, and scales form. ARCI-4B is autosomal recessive, which means a child gets one non-working gene from each parent, and both parents are usually healthy carriers. ARCI belongs to a group of non-syndromic ichthyoses (mainly skin problems) that include lamellar ichthyosis (LI) and congenital ichthyosiform erythroderma (CIE). First Skin Foundation+3NCBI+3PMC+3

Other names

• Autosomal recessive congenital ichthyosis, type 4B

• ALOX12B-related ARCI

• 12R-lipoxygenase–related ichthyosis

• Lamellar ichthyosis due to ALOX12B (many patients show a lamellar pattern)

• Congenital ichthyosiform erythroderma due to ALOX12B (others show more redness)

• Self-improving collodion baby (SICI) due to ALOX12B (in a subset, the newborn membrane improves quickly) Orpha+2Orpha+2

Types

ARCI-4B does not have strict “subtypes” of its own, but ALOX12B variants can present along the ARCI spectrum:

1. Lamellar ichthyosis phenotype – large, plate-like scales with little redness. Orpha

2. Congenital ichthyosiform erythroderma phenotype – finer scaling with more redness. Orpha

3. Self-improving collodion baby (SICI) – tight shiny skin at birth that improves within weeks to months; some residual dryness remains. PMC

4. Mixed/overlap pattern – features of both LI and CIE in the same person. NCBI

These patterns are all part of the same ALOX12B-related condition and can vary even within one family. NCBI

Causes

1. Gene variant in ALOX12B – the root cause; changes stop the 12R-lipoxygenase enzyme from making key skin lipids. ScienceDirect

2. Loss-of-function mutations – nonsense/frameshift variants create a short, non-working enzyme. PubMed

3. Missense mutations – single amino-acid changes distort the enzyme’s shape and activity. PubMed

4. Splice-site mutations – errors in cutting and joining RNA lead to faulty protein. ScienceDirect

5. Compound heterozygosity – two different harmful variants (one from each parent) combine to cause disease. NCBI

6. Homozygous variants – the same mutation on both copies, common in consanguineous families. Medical Journals Sweden

7. Disrupted epidermal lipoxygenase pathway – ALOX12B works with ALOXE3; pathway failure weakens the barrier. ScienceDirect

8. Abnormal skin-lipid processing – defective oxygenation of fatty acids lowers corneocyte “mortar.” PMC

9. Impaired cornification – the outer skin layer (stratum corneum) forms poorly; scales build up. NCBI

10. Increased transepidermal water loss (TEWL) – water escapes, causing dryness and scaling. NCBI

11. Modifier genes – other skin-barrier genes can worsen or soften the picture (research ongoing). JAMA Network

12. Founder effects – certain communities show more cases due to shared ancestry. actasdermo.org

13. Environmental dryness – dry, cold air dehydrates skin and reveals the barrier weakness. (Clinical consensus within ARCI care.) NCBI

14. Heat or fever – sweating problems make heat rashes and scaling worse. NCBI

15. Infections – skin cracks allow bacteria to enter and aggravate redness and scaling. NCBI

16. Irritating products – harsh soaps, fragrances, and alcohols strip the limited skin oils. NCBI

17. Poor humidity control – long exposure to air-conditioning or heaters without humidification dries skin further. NCBI

18. Nutritional stress or dehydration – less water intake and poor diet can worsen dryness (supportive care principle). NCBI

19. Mechanical friction – tight clothing and rubbing cause more scale and cracks. NCBI

20. Delayed or minimal emollient use – without regular moisturizers, the weak barrier cannot recover. NCBI

Symptoms

1. Collodion membrane at birth – shiny, tight film over the whole body that later peels. NCBI+1

2. Generalized scaling – dry flakes or thick plates cover most of the skin. Orpha

3. Redness (erythroderma) – common early; varies across life. Orpha

4. Tight skin – can pull the eyelids out (ectropion) and lips out (eclabium) in newborns. actasdermo.org

5. Cracks and fissures – painful splits where infection can start. NCBI

6. Itching or irritation – from dryness and small inflammation. NCBI

7. Heat intolerance – trouble sweating leads to overheating. NCBI

8. Palmar-plantar hyperkeratosis – thick skin on hands and feet. preventiongenetics.com

9. Alopecia or sparse hair – hair may be thin due to scaling around follicles. NCBI

10. Ear canal scaling – wax and scales can block hearing temporarily. NCBI

11. Eye irritation – exposure from ectropion dries the eye surface. NCBI

12. Nail changes – thickened or brittle nails in some patients. NCBI

13. Body odor issues – scales trap sweat and bacteria. NCBI

14. Self-improving course in some – after the collodion stage, skin becomes much milder (SICI). PMC

15. Psychosocial stress – visible skin differences can affect confidence and social life. NCBI

Diagnostic tests

A) Physical examination (bedside)

1. Full-body skin exam – doctors look at scale type (large “plates” vs fine), redness, and distribution to place the phenotype within LI/CIE spectrum. This first step guides the rest of testing. NCBI

2. Newborn review for collodion membrane – confirms congenital onset and helps separate ARCI from later-onset disorders. NCBI+1

3. Eyelid and lip inspection – checks for ectropion/eclabium that need urgent eye-lubrication and feeding support. actasdermo.org

4. Hand/foot assessment – looks for palmar-plantar thickening that is common in ARCI. preventiongenetics.com

5. Temperature and hydration status – screens heat intolerance and water loss risk in babies with erythroderma. NCBI

B) “Manual” or bedside functional tests (simple tools, clinic)

6. Transepidermal Water Loss (TEWL) measurement – a handheld probe measures water escape from skin; high TEWL supports a barrier defect. It is non-invasive and quick. NCBI

7. Skin pH measurement – abnormal surface pH can hint at barrier weakness and guides emollient choice. (Supportive assessment in barrier disorders.) NCBI

8. Emollient response trial – doctors test rich moisturizers/occlusives and see if scaling and tightness soften; this helps care planning (not a replacement for genetic testing). NCBI

9. Photographic documentation – serial photos track severity and response, useful in long-term management and research. NCBI

C) Laboratory & pathological tests

10. Genetic testing (targeted ALOX12B sequencing) – the key confirmatory test; finds pathogenic variants and confirms ARCI-4B. Panels often include ALOX12B, ALOXE3, TGM1, NIPAL4, ABCA12, CYP4F22, and others. NCBI+2actasdermo.org+2

11. ARCI multi-gene panel or exome – used when single-gene testing is negative or there is diagnostic doubt; captures rare or novel variants. NCBI

12. Skin biopsy (histology) – may show hyperkeratosis and compact scaling; helpful when genetics are not immediately available or to rule out mimics. actasdermo.org

13. Electron microscopy (if accessible) – can show abnormalities in lipid lamellae and corneocyte structure; supports a barrier lipid defect. ScienceDirect

14. Rule-out labs for syndromic ichthyoses – basic blood work or targeted tests to exclude conditions where ichthyosis is part of a broader syndrome (as directed by history). JAMA Network

15. Infection screens from skin fissures – cultures when there are signs of bacterial infection; important for safe care. NCBI

D) Electrodiagnostic (usually not required but sometimes helpful)

16. Skin bioimpedance spectroscopy – a non-invasive device that estimates skin hydration by measuring electrical resistance; can monitor barrier function over time (a supportive metric, not diagnostic on its own). (Applied research/adjunct in barrier disorders.) NCBI

17. Ocular surface tests (e.g., tear film break-up time) – simple clinical “electrical/optical” instruments used by eye doctors if ectropion exposes the eyes; helps protect vision. (Supportive, when eye symptoms exist.) NCBI

Note: Standard nerve conduction or muscle electrodiagnostic tests are not part of routine ARCI work-up because ARCI-4B is a skin-limited (non-syndromic) disorder. JAMA Network

E) Imaging tests (selective)

18. Ophthalmic imaging (slit-lamp photos) – documents eye surface dryness or exposure damage in ectropion; guides lubrication and referral. NCBI

19. Dermatoscopic imaging – magnified skin images can track scale pattern and guide gentle scale removal strategies. (Adjunct tool.) NCBI

20. General imaging is rarely needed – X-rays/ultrasound/CT/MRI are not routine for ARCI itself; they are used only to evaluate complications unrelated to the skin. NCBI

Non-pharmacological treatments (therapies & others)

1. Warm, humidified incubator care (newborn)
   Purpose: protect from heat/water loss and help breathing.
   Mechanism: humidity softens thick plates and reduces evaporation; warmth prevents hypothermia while the barrier is weak. This is a core part of NICU support that improved survival in HI. JAMA Network

2. Liberal emollients/occlusives (petrolatum, bland ointments)
   Purpose: soften plates, reduce fissures, keep water in the skin.
   Mechanism: occlusive layers slow water loss and mechanically loosen scale; petrolatum-type protectants are recognized under the FDA OTC skin-protectant monograph. FDA Access Data

3. Frequent sterile saline soaks & careful debridement
   Purpose: gradually loosen plates and reduce painful cracks.
   Mechanism: hydration swells the outer layer; gentle debridement avoids tearing new skin and helps movement. (Standard NICU/dermatology supportive practice reported across reviews.) MDPI+1

4. Eye protection & lubrication
   Purpose: protect the exposed cornea from drying and ulcers due to ectropion.
   Mechanism: scheduled ointments/drops, moisture chambers, and taping/massage restore lid-cornea contact; surgery is considered if exposure persists. ichthyosis.org.uk+1

5. Thermoregulation & fluid/electrolyte management
   Purpose: prevent dehydration and salt/temperature problems.
   Mechanism: barrier failure causes massive transepidermal water loss; careful fluids and temperature control counter this. NCBI

6. Infection prevention & wound care
   Purpose: reduce high sepsis risk from skin cracks.
   Mechanism: hand hygiene, culture-guided cleansing, and barrier repair decrease bacterial entry points; targeted antibiotics only when infection is suspected/confirmed. BioMed Central

7. Early physical/occupational therapy and splinting
   Purpose: maintain range of motion and prevent contractures.
   Mechanism: as plates soften, guided movement and gentle splints limit tendon/skin tightening around joints. MDPI

8. Genetic counseling
   Purpose: help parents understand recurrence risk (autosomal recessive) and testing options for future pregnancies.
   Mechanism: explains ABCA12 inheritance and carrier testing. NCBI

9. Sun/heat management & sweat support
   Purpose: prevent overheating since sweat ducts can be blocked and the barrier leaks.
   Mechanism: cool environment, fluids, light clothing, fans/AC, and scheduled breaks prevent heat stress. Skin Therapy Letter

10. Psychosocial & caregiver support
    Purpose: reduce caregiver burden and improve quality of life.
    Mechanism: structured education, support groups, and mental-health access address the substantial family impact documented in ARCI. BioMed Central

11. Ongoing ophthalmology follow-up
    Purpose: detect corneal damage early.
    Mechanism: serial slit-lamp checks and protective measures prevent ulcers; consider surgical eyelid procedures if exposure persists. ScienceDirect

12. ENT & feeding support in infants
    Purpose: help feeding/breathing when mouth opening is limited by plates.
    Mechanism: coordinated NICU care (nipple shields, NG feeds if needed) while retinoids/skin care improve mouth mobility. MDPI

13. Dermatology-led skin routines (lifelong)
    Purpose: daily scale control to improve comfort and function.
    Mechanism: emollients, keratolytics, and timed bathing form the backbone of chronic care. BioMed Central

14. Ectropion massage & eyelid emollients
    Purpose: support eyelid closure in mild cases.
    Mechanism: emollient massage can partially reverse eyelid retraction, especially in infants. ichthyosis.org.uk

15. Temperature-neutral bathing with non-soap cleansers
    Purpose: remove scale without stripping lipids.
    Mechanism: mild cleansers keep pH closer to physiologic and reduce irritation/infection risk. Skin Therapy Letter

16. Nail and fissure care
    Purpose: prevent secondary infection and pain.
    Mechanism: trim/smooth nails; close attention to heel/hand fissures with occlusion and gentle keratolysis. BioMed Central

17. School/work accommodations
    Purpose: support attendance and performance.
    Mechanism: extra hydration breaks, climate control, and skin-care time allowances reduce flares. Skin Therapy Letter

18. Vaccination on schedule
    Purpose: minimize infection risk.
    Mechanism: normal immunization timetables protect against preventable diseases when barrier defenses are weak. NCBI

19. Fertility/pregnancy counseling in retinoid users
    Purpose: prevent fetal exposure.
    Mechanism: iPLEDGE in isotretinoin and strict contraception windows for acitretin are mandatory. FDA Access Data+1

20. Clinical-trial awareness (gene/cell therapy research)
    Purpose: access emerging options under study.
    Mechanism: ARCI gene/cell therapy is experimental; participation occurs only via regulated trials. MDPI

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Drug treatments

No drug is FDA-approved specifically for Harlequin ichthyosis. Many centers use retinoids off-label in neonatal HI to soften plates and improve survival; all retinoids have strict safety rules, especially around pregnancy. PMC+1

1. Acitretin (Soriatane®) – oral retinoid
   Class/Dose/Time: Retinoid; adults often 10–25 mg daily (labels specify psoriasis; pediatric/HI use is off-label with specialist dosing). Purpose: reduce hyperkeratosis, improve flexibility. Mechanism: normalizes keratinocyte differentiation. Major risks: boxed teratogenicity; long contraception window (≥3 years after stopping). Source: FDA label. FDA Access Data+1

2. Isotretinoin (Absorica®/Absorica LD™) – oral retinoid
   Class/Dose/Time: Retinoid; acne label uses ~0.5–1 mg/kg/day; neonatal HI reports start early at specialist doses. Purpose: soften plates, speed eye/mouth closure, improve movement. Mechanism: reduces cornified envelope and scale buildup. Risks: boxed embryo-fetal toxicity; iPLEDGE; liver/lipid monitoring. Source: FDA label; survival benefit reported in case series. FDA Access Data+2FDA Access Data+2

3. Tazarotene (Tazorac®/Avage®) – topical retinoid (adjunct)
   Class/Dose/Time: Topical retinoid gels/creams once daily to limited areas (label indications differ); in ARCI, used sparingly on thick plaques. Purpose: focal scale reduction. Mechanism: RAR-mediated normalization of epidermal differentiation. Risks: irritation; pregnancy contraindications. Source: FDA labels. FDA Access Data+1

4. Ammonium lactate 12% (Lac-Hydrin®) – keratolytic/emollient
   Class/Dose/Time: Topical lotion/cream, 1–2×/day. Purpose: soften and shed scales. Mechanism: lactic acid loosens corneodesmosomes and hydrates stratum corneum. Risks: stinging on fissures/sun-exposed areas. Source: FDA labels. FDA Access Data+1

5. Urea 20–40% creams/ointments – keratolytic/emollient
   Class/Dose/Time: Topical 1–2×/day to thick scale. Purpose: soften hyperkeratosis and fissures. Mechanism: breaks hydrogen bonds in keratin to reduce cohesion. Risks: stinging; avoid eyes/mucosa. Source: FDA DailyMed/FDA SPL. DailyMed+1

6. Petrolatum-based OTC skin protectants
   Class/Dose/Time: As needed, many times/day. Purpose: seal in moisture, reduce TEWL, protect wounds. Mechanism: occlusive barrier per FDA OTC Skin Protectant Monograph. Risks: minimal; avoid contaminated jars. Source: FDA monograph. FDA Access Data

7. Mupirocin 2% (Bactroban®) ointment/cream – topical antibiotic (when infected)
   Class/Dose/Time: Apply 3×/day for 5–10 days per label. Purpose: treat localized impetiginized fissures (S. aureus/S. pyogenes). Mechanism: inhibits isoleucyl-tRNA synthetase. Risks: local irritation; PEG base caution on large wounds. Source: FDA labels. FDA Access Data+1

8. Ofloxacin or levofloxacin ophthalmic drops – ocular antibiotic (when exposure keratopathy gets infected)
   Class/Dose/Time: Label-directed dosing for bacterial conjunctivitis/ulcer. Purpose: treat proven ocular infection over exposed corneas. Mechanism: fluoroquinolone DNA-gyrase inhibition. Risks: transient burning; hypersensitivity. Source: FDA labels. FDA Access Data+1

9. Erythromycin ophthalmic ointment – ocular antibiotic prophylaxis/treatment
   Class/Dose/Time: Ribbon to lower lid per label. Purpose: protect compromised corneas overnight when lids don’t close. Mechanism: macrolide ribosomal inhibition. Risks: blurred vision; hypersensitivity. Source: FDA/EM guidance. DailyMed+1

10. Analgesics (acetaminophen/ibuprofen) – pain control for fissures
    Class/Dose/Time: Label doses; weight-based in children. Purpose: reduce pain → better feeding/movement. Mechanism: central COX inhibition (acetaminophen) / peripheral COX inhibition (ibuprofen). Risks: hepatotoxicity (acetaminophen), GI/renal (NSAIDs). Source: FDA consumer/labeling standards. FDA Access Data

11. Lubricating eye ointments (petrolatum-based)
    Purpose: continuous corneal surface protection when blinking is incomplete. Mechanism: thick occlusive layer reduces evaporation. Source: FDA OTC skin protectant monograph (occlusive petrolatum). FDA Access Data

12. Barrier repair with ammonium lactate + petrolatum layering
    Purpose: combined humectant + occlusive strategy to keep plates supple. Mechanism: lactate draws/holds water, petrolatum seals it in. Source: FDA labels/monograph. FDA Access Data+1

13. Short courses of systemic antibiotics (culture-guided)
    Purpose: treat sepsis/cellulitis; agents per susceptibility. Mechanism: systemic eradication of invading bacteria through fissures. Source: general ARCI/HI reviews. BioMed Central

14. Vitamin D supplementation (if deficient)
    Purpose: address deficiency from limited outdoor exposure/skin barrier issues. Mechanism: restores bone/immune function; not HI-specific. Source: review noting alternatives/adjuncts in HI care. MDPI

15. Topical keratolytic rotation (urea ↔ ammonium lactate)
    Purpose: reduce irritation and tachyphylaxis. Mechanism: alternate mechanisms of corneocyte cohesion reduction. Source: FDA labels. DailyMed+1

16. Topical retinoid “micro-areas” for problematic plaques
    Purpose: focus efficacy while limiting irritation. Mechanism: localized RAR activation to normalize cornification. Source: FDA tazarotene label. FDA Access Data

17. Petrolatum-impregnated dressings for deep fissures
    Purpose: moist wound healing and pain relief. Mechanism: occlusion and low-adherence contact layers. Source: OTC monograph principles. FDA Access Data

18. Antipruritics (sedating antihistamines at night, label-dosed)
    Purpose: improve sleep and reduce scratching. Mechanism: central sedation + antihistamine effect; not disease-modifying. Source: standard symptomatic care references for ichthyoses. Skin Therapy Letter

19. Lipid-rich moisturizers between keratolytics
    Purpose: replenish some surface lipids while ABCA12 pathway is defective. Mechanism: exogenous lipids fill gaps and reduce TEWL. Source: management reviews. BioMed Central

20. Close lab monitoring with systemic retinoids
    Purpose: detect hepatotoxicity/lipid abnormalities early. Mechanism: scheduled labs + dose adjustments per label warnings. Source: FDA retinoid labels. FDA Access Data+1

Dietary molecular supplements

1. Vitamin D – If blood levels are low. Dose: per labs (often 600–1000 IU/day in children, clinician-adjusted). Function: bone/immune support; may be low due to sun avoidance. Mechanism: endocrine effects on calcium/immune cells; not barrier-specific. MDPI

2. Omega-3 fatty acids – Dose: label-directed capsules. Function: anti-inflammatory and barrier support. Mechanism: modifies eicosanoid profile; adjunct only. BioMed Central

3. Biotin (if brittle nails/fissures) – Dose: per label. Function: nail integrity. Mechanism: cofactor in keratin structure; evidence modest. BioMed Central

4. Zinc (if deficient) – Dose: per labs. Function: wound healing/immune. Mechanism: cofactor for epithelial enzymes. BioMed Central

5. Iron (if anemic) – Dose: per labs. Function: energy/immune. Mechanism: hemoglobin synthesis support. BioMed Central

6. Protein-adequate diet – Amount: age-appropriate RDA. Function: tissue repair. Mechanism: provides amino acids for barrier proteins. BioMed Central

7. Ceramide-rich topical nutrition (cosmetic-grade creams) – Use: twice daily. Function: replenish missing lipids; though ABCA12 transports specific acylceramides, exogenous lipids can help water retention. Mechanism: fills lipid lamellae gaps superficially. BioMed Central

8. Electrolyte solutions during heat – Use: as needed. Function: replace salt/water losses. Mechanism: corrects barrier-related fluid loss. NCBI

9. Multivitamin (age-appropriate) – Use: daily. Function: cover dietary gaps in chronic disease. Mechanism: broad micronutrient support. BioMed Central

10. Calcium (if low with vitamin D therapy) – Dose: per age and labs. Function: bone health. Mechanism: works with vitamin D to mineralize bone. BioMed Central

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Immunity-booster / regenerative / stem-cell drugs

Transparent reality check: There are no FDA-approved immune-booster, regenerative, or stem-cell drugs for ARCI-4B/Harlequin ichthyosis. Any such claims would be inaccurate. Care is supportive; systemic retinoids are off-label for HI; gene/cell therapy remains experimental in research settings only. If you see “stem-cell cures” marketed for ichthyosis, be cautious and verify via ClinicalTrials.gov and ethics boards. MDPI

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Surgeries/procedures

1. Temporary or permanent tarsorrhaphy
   Why: protect exposed cornea when eyelids cannot close due to ectropion.
   Mechanism: partially sutures lids together to keep the eye moist and safe. Cleveland Clinic

2. Ectropion repair with skin grafts (including bioengineered grafts)
   Why: restore eyelid position to shield the cornea.
   Mechanism: lengthens the front eyelid lamella; graft replaces tight skin. PubMed+1

3. Release of digital constriction bands/contractures
   Why: prevent ischemia and enable growth/motion of fingers/toes.
   Mechanism: surgical division of tight skin rings and scar remodeling. MDPI

4. Debridement/“escharotomy-like” fissure care
   Why: relieve restrictive plates that impair breathing/feeding/circulation.
   Mechanism: controlled removal/loosening of rigid plates in NICU setting. MDPI

5. Corneal surface procedures (if ulcers develop)
   Why: treat non-healing corneal defects from exposure.
   Mechanism: bandage contact lens or surgical approaches as per ophthalmology. ScienceDirect

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Preventions

1. Maintain daily emollient routine to avoid fissures and infections. BioMed Central

2. Avoid overheating; use fans/AC, hydration, and rest breaks in hot weather. Skin Therapy Letter

3. Keep nails short and use cotton gloves at night to reduce scratching injury. Skin Therapy Letter

4. Use non-soap cleansers and lukewarm baths; pat dry and immediately moisturize. Skin Therapy Letter

5. Hand hygiene and rapid care of any red, oozing fissure. BioMed Central

6. Eye lubrication schedule and early ophthalmology review for irritation/redness. ScienceDirect

7. Heat action plan (cool packs, shade, electrolyte drinks). NCBI

8. Medication safety with retinoids (pregnancy prevention, lab checks). FDA Access Data+1

9. Vaccinations up to date. NCBI

10. Education & support for caregivers to reduce stress and improve adherence. BioMed Central

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When to see a doctor urgently

See a clinician now for fever, spreading redness, pus, foul odor from skin, eye pain/light sensitivity, reduced feeding or lethargy, fast breathing, poor wet diapers, vomiting, or sudden worsening tightness of rings around fingers/toes. These may signal infection, dehydration, eye injury, or restricted circulation and need urgent assessment. BioMed Central

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What to eat & what to avoid

Eat: enough calories (growth and wound repair need extra energy), protein with every meal (eggs, fish, beans), fruits/vegetables, whole grains, and fluids/electrolytes in hot weather. Discuss vitamin D and calcium if sun exposure is limited. MDPI

Avoid/limit: very hot, spicy foods if they trigger flushing/itch; dehydrating drinks in heat; unnecessary supplements without labs; and “miracle” products claiming cures. Coordinate any diet changes with your clinician—especially if using retinoids, where pregnancy prevention and liver/lipid checks are essential. FDA Access Data+1

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FAQs

1) Is ARCI-4B the same as Harlequin ichthyosis?
Yes. ARCI-4B corresponds to Harlequin ichthyosis caused most often by ABCA12 variants. NCBI+1

2) Is there a cure?
No cure yet; care is supportive. Gene/cell therapies are in research. MDPI

3) Why do retinoids help?
They normalize how skin cells mature, which softens thick plates and improves movement/eye closing in many infants. PMC

4) Are retinoids approved for HI?
No; use is off-label with strict safety monitoring. PMC

5) Do retinoids improve survival?
Case series suggest higher survival with early neonatal retinoids plus modern NICU care. JAMA Network+1

6) What about topical retinoids?
They can soften focal plaques but often irritate; systemic agents are more impactful in severe generalized disease. FDA Access Data

7) Why is eye care so important?
Ectropion exposes the cornea and can cause ulcers; lubricant and, if needed, eyelid surgery protect vision. ScienceDirect

8) Can infections be prevented?
Good skin care, swift fissure care, and hygiene help. Use antibiotics only when infection is suspected/confirmed. BioMed Central

9) Is sweating affected?
Yes—blocked ducts and barrier issues raise overheating risk; active cooling and fluids help. Skin Therapy Letter

10) What causes ARCI-4B genetically?
Biallelic pathogenic variants in ABCA12, a lipid transporter required for the skin barrier. preventiongenetics.com

11) Can parents be tested?
Yes—carrier testing and prenatal options are available via genetics services. NCBI

12) Are biologics helpful?
Evidence is emerging in broader congenital ichthyoses, but data are limited; not HI-specific approvals. OUP Academic

13) Are surgeries common?
Selective—mostly eyelid procedures and release of tight bands when conservative care fails. PubMed

14) What is the long-term outlook?
Survival is better than in the past; lifelong skin care is needed and quality of life can be good with support. JAMA Network

15) Where can I read a clinical overview?
See GeneReviews (ARCI) and recent reviews on treatment advances. NCBI+1

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members

Last Updated: October 06, 2025.

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