128 Chapter 6
Common Disease, Disorder, or ConditionRingworm continuedParonychia, Onychomycosis, And Onychocryptosis^
Paronychia (par-oh-NIK-e-ah) occurs when the fold of skin at the edge of the nail becomes-
infected (Figure 6-11A).^
Onychomycosis (on-e-koh-my-KOH-sis) is a fungal infection of the nails resulting in
dry, thickened, and brittle nails, usually accompanied by a yellowish discoloration (-Figure 6-
11B). It is very difficult to treat as topical applications are ineffective.^
Onychocryptosis (on-e-koh-crypt-TOE-sis) is known as an ingrown toenail (Figure 6-
11C). It occurs when the lateral distal margin of the nail grows into or is pressed into the skin
of a toe causing inflammation. Prevention of the condition is -accomplished by wearing
proper shoes and correctly aligned trimming of the toe nails.
Skin Lesions^
Various surface lesions can develop on the skin (Figure 6-12). A papule is a skin lesion- that
is a solid, small elevation less than 1 cm in diameter. A macule is a flat, small discoloration
of the skin that is even with the skin surface. A small rash can be considered a macule. A
wheal is a pale or reddened elevation produced by a localized edema or swelling, like that
caused by a mosquito bite. A crust is a hard, solid layer on the surface of the skin caused by
dried blood, serum, or pus. It is also referred to as a scab. A furuncle or boil is a
Staphylococcus infection of a hair follicle or gland with pus formation. It is character-ized by
swelling, pain, and redness. It is treated with antibiotics and surgical removal usually in a
doctor’s office. A bulla or vesicle is a thin blister of the skin containing clear, serous fluid. It
is usually larger than 1 cm in diameter. A pustule is a small elevation of the skin, similar to a
vesicle or bulla, but is filled with pus. They are usually less than 1 cm in diameter. A cyst is
an encapsulated sac in the dermis or under the skin in the subcutane-ous tissue. It is lined
with epithelium and can contain either fluid or a semisolid mass.
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2016
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(A) (B)
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(C)^
Figure 6- 11 (A) Paronychia, (B) onychomycosis, (C) onychocryptosis.