Non-Invasive Imaging of Netherton Syndrome with Reflectance Confocal Microscopy and Line-Field Confocal Optical Coherence Tomography

Introduction:
Netherton syndrome is a genodermatosis caused by a muta­tion in the SPINK5 gene, which encodes serine protease inhibitor LEKTI. LEKTI deficiency overactivates kallikrein-related peptidases, causing epidermal and hair shaft keratinization abnormalities. The characteristic clinical triad includes congenital ichthyosiform erythroderma or ichthyo­sis linearis circumflexa, atopic diathesis and trichorrhexis invaginata.

Objective:
To demonstrate how reflectance confocal microscopy and line-field confocal optical coherence tomography support the diagnosis of Netherton syndrome.

Case report:
A 3-year-old girl presented with erythematous, polycyclic plaques with peripheral scaling located on the face, trunk, upper and lower extremities. Trichoscopy showed bamboo hairs and golf tee-like endings. Reflectance confocal microscopy and line-field confocal optical coherence tomography revealed scale, parakeratosis, acanthosis, spongiosis and perivascular inflammatory infiltrates, which were confirmed by histopathological examination.

Conclusions:
Trichoscopy, reflectance confocal microscopy and linefield confocal optical coherence tomography can facilitate the diagnosis of patients presenting with eczema-like lesions and brittle hair to identify Netherton syndrome. To our knowledge, this is the first line-field confocal optical coherence tomography documentation of Netherton syndrome.