Abnormal thickening of the skin localized to the palm of the hand and the sole of the foot.

An abnormality of the skin characterized the presence of excessive amounts of dry surface scales on the skin resulting from an abnormality of keratinization.

Redness of the skin, caused by hyperemia of the capillaries in the lower layers of the skin.

Epidermolytic hyperkeratosis is a skin disorder that is present at birth. Affected babies may have very red skin (erythroderma) and severe blisters. Because newborns with this disorder are missing the protection provided by normal skin, they are at risk of becoming dehydrated and developing infections in the skin or throughout the body (sepsis).\n\nAs affected individuals get older, blistering is less frequent, erythroderma becomes less evident, and the skin becomes thick (hyperkeratotic), especially over joints, on areas of skin that come into contact with each other, or on the scalp or neck. This thickened skin is usually darker than normal. Bacteria can grow in the thick skin, often causing a distinct odor.\n\nEpidermolytic hyperkeratosis can be categorized into two types. People with PS-type epidermolytic hyperkeratosis have thick skin on the palms of their hands and soles of their feet (palmoplantar or palm/sole hyperkeratosis) in addition to other areas of the body. People with the other type, NPS-type, do not have extensive palmoplantar hyperkeratosis but do have hyperkeratosis on other areas of the body.\n\nEpidermolytic hyperkeratosis is part of a group of conditions called ichthyoses, which refers to the scaly skin seen in individuals with related disorders. However, in epidermolytic hyperkeratosis, the skin is thick but not scaly as in some of the other conditions in the group.

An abnormality of the hair.

Refers to the loss of the outer layer of the epidermis in large, scale-like flakes.

A plaque (a solid, raised, plateau-like (flat-topped) lesion greater than 1 cm in diameter) with a red or reddish color often associated with inflammation or irritation.

Abnormal structure or appearance of the nail.

Abnormal keratinization of the epidermal stratum coreum (horny layer) with increased keratin formation, preservation of the nuclei in the superficial cells, and absence of the stratum granulosum.

Formation of an anuclear keratin layer

The presence of one or more bullae on the skin, defined as fluid-filled blisters more than 5 mm in diameter with thin walls.

A discontinuity of the skin exhibiting incomplete loss of the epidermis, a lesion that is moist, circumscribed, and usually depressed.

Lichenification affecting primarily flexural areas of the skin.