The term ectodermal dysplasias (EDs) describes a heterogeneous group of inherited developmental disorders that affect several tissues of ectodermal origin. The most common form of EDs is hypohidrotic ectodermal dysplasia (HED), which is characterized by hypodontia, hypotrichosis, and partial or total eccrine sweat gland deficiency. HED is estimated to affect at least 1 in 17,000 people worldwide. Patients with HED have characteristic facies with periorbital hyperpigmentation, depressed nasal bridge, malar hypoplasia, and absent or sparse eyebrows and eyelashes. The common ocular features of HED include madarosis, trichiasis, and ocular chronic surface disease due to dry eye syndrome, which manifests clinically with discomfort, photophobia, and redness. Dry eye is common in HED and results from a combination of ocular surface defects: mucus abnormalities (abnormal conjunctival mucinous glands), aqueous tear deficiency (abnormalities in the lacrimal gland) and lipid deficiency (due to the partial or total absence of the meibomian glands; modified sebaceous glands with the tarsal plate). Sight-threatening complications result from ocular surface disease, including corneal ulceration and perforation with subsequent corneal scarring and neovascularization. Rare ocular features have been reported and include bilateral or unilateral congenital cataracts, bilateral glaucoma, chorioretinal atrophy and atresia of the nasolacrimal duct. Recognition of the ocular manifestations of HED is required to perform clinical surveillance, instigate supportive and preventative treatment, and manage ocular complications.

In “Clinical Aspects and Differential Diagnosis of Atopic Dermatitis” the clinical features of atopic dermatitis (AD) are discussed including acute, subacute, and chronic eczema and secondary lesions, as well as the presentation of AD in infants, children, adults (including pregnancy), and the elderly. We discuss diagnosing AD (medical history, exam, labs like IgE), outline the Hanifin and Rajka major and minor criteria, and the UK Working Party criteria, as well as comorbidities of AD (asthma, allergies, eye comorbidities, sleep, ADHD, anxiety, depression) and skin infections in AD patients (staph aureus, molluscum contagiosum, warts, eczema herpeticum, eczema coxsackium, eczema vaccinatum). We give a differential diagnosis of atopic dermatitis by location, morphology, and age. We also discuss other diseases with eczematous presentations such as genetic disorders like ectodermal dysplasia, primary immunodeficiency disorders and other acquired diseases like dermatitis herpetiformis, graft vs. host disease, and so on. There are many photos of patients with clinical signs of atopic dermatitis and clinical pictures of diseases that are on the differential diagnosis of AD. <!----> <!----> <!----> <!---->