Ichthyosis

Temperature - Barrier loss impairs thermoregulation and sweat gland function, so these patients both lose heat through evaporation and lose the ability to shed it. Warm and humidify the room before the patient arrives, use forced air and warmed fluids, and follow core temperature continuously rather than spot-checking.

Fluid and electrolytes - Send a basic metabolic panel and follow urine output and daily weights. Transepidermal water loss through a defective barrier produces free water and electrolyte losses that are invisible on a standard fluid calculation, and neonates with severe disease are managed on exactly these three measures.

Skin handling and adhesives - Every fissure is an open door for bacteria, and the scale is what is left of the barrier. Pad and secure lines, electrodes, and the BP cuff without stripping skin, and treat any new break as a site that will need topical antibiotic coverage.

Infection - Severe congenital ichthyosis carries a high mortality from fulminant sepsis, and deep fissures are the entry point. Check WBC with differential and send blood cultures if the patient is febrile, unstable, or lethargic, and hold a strict aseptic line for every access.

Eyes - Ectropion turns the lids out and exposes the conjunctiva, leaving the cornea at risk for abrasion and desiccation. Lubricate generously and shield the eye deliberately; taping lids that will not appose does not protect the cornea.

Chest wall and ventilation in severe disease - Hyperkeratotic plates over the chest restrict expansion and produce hypoventilation and respiratory failure. Look at chest excursion and tidal volumes at baseline, expect restrictive mechanics, and plan controlled ventilation rather than counting on spontaneous respiration.

Airway anatomy - In harlequin and other severe subtypes the nares can be obstructed by overlying skin, the nose is flattened, and eclabium everts the lips into a fixed gaping mouth. Check nasal patency by hand before planning a nasal airway or NG tube, and look at mouth opening and lip mobility before assuming a mask will seal.

Positioning and distal perfusion - Pseudo-contractures from the tension of hyperkeratotic plates restrict limb movement and impair perfusion; digital pallor and ischemic necrosis of distal extremities are described. Position within the range the plates allow, check color and capillary refill after every move, and remember a pulse oximeter on an encased digit may not track.

Vascular access - Thick adherent scale sits over the extensor surfaces, lower limbs, and palms and soles, which is where you normally look. Reach for ultrasound early rather than working through scale on landmarks.

Reactive airway - Between 25% and 50% of ichthyosis vulgaris patients have associated atopic dermatitis, asthma, and hay fever. Ask about inhaler use and recent exacerbations, listen for wheeze, and have the patient bring their rescue inhaler.

Home therapy and systemic absorption - Ask what is on the skin and what is systemic. Keratolytics containing salicylic acid, urea, or lactic acid applied over a large body surface area can be absorbed systemically with associated toxicity, particularly in children, and severe disease is treated with oral retinoids such as acitretin.

New-onset ichthyosis in an adult - Acquired ichthyosis points to something else: lymphoma, myeloma, cutaneous T-cell lymphoma, SLE, HIV, malabsorption, or a drug. Track down which one, because that disease and not the skin will drive the anesthetic.

Ichthyosis is a family of disorders of cornification in which the epidermal barrier fails and scale accumulates. Ichthyosis vulgaris, the most common form at roughly 1 in 100 to 250, comes from loss-of-function FLG mutations that leave filaggrin deficient, disrupting the cornified cell envelope and driving excessive transepidermal water loss. X-linked ichthyosis reflects steroid sulfatase deficiency and retention hyperkeratosis. Harlequin ichthyosis, the most severe subtype, comes from ABCA12 mutations that block lipid transport into the stratum corneum; neonates are encased in armor-like plates separated by deep fissures.

Acquired ichthyosis instead tracks an underlying disease - Hodgkin lymphoma, myeloma, cutaneous T-cell lymphoma, SLE, AIDS, malabsorption - or a drug such as allopurinol or an EGFR or BRAF inhibitor.

Whatever the subtype, the perioperative problem is the same: skin that no longer holds in water and heat or keeps bacteria out, over a mechanical barrier that is thickened, fissured, and easily torn.