The term, autosomal recessive congenital ichthyosis (ARCI), describes a group of rare genetic skin diseases of cornification involving hyperkeratotic scaling at birth. The defective skin barrier function may lead to dehydration, body temperature instability, and high susceptibility to infections. In most cases of ARCI, neonates are born with a collodion membrane covering the body, often presenting with ectropion and eclabium. We report a premature female neonate presenting with hyperkeratotic scaling at birth without a collodion membrane. She was managed with placement in a humidified isolette, prophylactic antibiotics, dilute bleach baths, petrolatum ointment, and artificial eye drops. By the fourth week of life, there was marked improvement in her skin with the large, brown, plate-like scales on the trunk and extremities becoming lighter in color and finer in appearance. The ichthyosis genetic panel showed mutations in the ABCA12 gene resulting in the lamellar ichthyosis phenotype of ARCI. Our literature review revealed at least 28 patients with ARCI who were not born as collodion babies. Although collodion babies are a hallmark of most ARCI cases, clinicians should be aware of neonates with ARCI born without a collodion membrane and expedite appropriate workup and treatment.

BACKGROUND. Corneocytes of the nail plate, like those of the stratum corneum, generate cornified envelopes (CEs) of cross-linked protein that can be visualized readily after removal of non-cross-linked protein by detergent extraction. Defective CE formation occurs in epidermal scale and hair in transglutaminase 1 (TGM1)-negative lamellar ichthyosis (LI) and has been proposed as a diagnostic aid for this syndrome. OBJECTIVES. (i) To ascertain whether TGM1 is important for CE formation in nail; (ii) to characterize CE abnormalities occurring in LI that may be distinguished from other types of inherited ichthyosis when nail samples are subjected to detergent extraction; and (iii) to evaluate the utility of nails as a diagnostic aid for LI. METHODS. Nail samples were provided by nine patients previously classified as having TGM1-negative LI, four with other types of ichthyotic conditions and six normal controls. Samples were extracted extensively in sodium dodecyl sulphate under reducing conditions and examined by light and electron microscopy. RESULTS. After extraction, defective CE cross-linking was visualized in epidermal corneocytes from seven of nine patients exhibiting TGM1-negative LI, whereas nail samples from patients with the other syndromes were normal. The defects in CE structure resembled those recently reported for LI scale, although in some cases residual CE and CE-associated structures were present. CONCLUSIONS. Despite the paucity of clinical nail symptoms in LI, TGM1 activity is important for generation of normal CE in nail plate, consistent with its importance in protein cross-linking in interfollicular epidermis and hair. Lack of this activity leads to a strikingly aberrant appearance of CE in LI nail after detergent extraction that is evident ultrastructurally in a large majority of cases. Nail envelopes therefore could provide a useful diagnostic tool in distinguishing LI from other ichthyoses with overlapping clinical features.

Cutaneous adverse events are commonly experienced with use of tyrosine kinase inhibitors in the treatment of leukemia and typically include nonspecific cutaneous eruptions and xerosis. We report the case of a man who experienced an ichthyosiform drug eruption while taking ponatinib, a third-generation tyrosine kinase inhibitor. Disruption of epidermal growth pathways through inhibition of various receptor tyrosine kinases by ponatinib may offer insights into the pathophysiologic mechanisms behind acquired ichthyosis.