Keloid. Spontaneous keloids on the chest of an adolescent.
Diaper rash appears on the skin under a diaper. Diaper rash typically occurs in infants and children younger than 2 years, but the rash can also be seen in people who are incontinent or paralyzed.
Allergic Contact Dermatitis on Arm
Allergic contact dermatitis (reaction to temporary tattoo). Contact allergy to temporary tattoos has become an increasingly common phenomenon. In most cases, the tattoo material does not contain pure henna, but is a mixture of brown henna with paraphenylenediamine (PPD) called black henna. The patient is allergic to PPD in the tatto. In fact, the concentration of PPD in black henna is higher than that seen in commercial hair dyes. After resolution of the eczematous skin eruption, postinflammatory hyperpigmentation may persist for a considerable period of time.
Fire Ant Bites
A fire ant attaches to a person by biting with its jaws. Then, pivoting its head, it stings from its belly in a circular pattern at multiple sites.
Ringworm of the Body (Tinea Corporis)
Ringworm of the skin usually causes a very itchy rash. It often makes a pattern in the shape of a ring, but not always.
Twin-to-twin “transfusion”. Twins who develop with some form of common circulation in utero may show a temporary difference of cutaneous color related to oddities of hemodynamics. In the figure, one sees twin neonates, of whom the one on the right is uniformly and abnormally erythematous, whereas the other is abnormally pallid. The one looks plethoric, the other, anemic. In the course of time, restoration of normal blood counts and color will develop in both.
Hereditary Hemorrhagic Telangiectasia
Hereditary hemorrhagic telangiectasia. Punctuate hemorrhagic macules on the finger.
Trichotillomania. This is a form of alopecia that is caused by the child’s twisting or pulling of his or her own hair. This cause of hair loss is usually easy to recognize. There is often, but not always, a parental awareness of hair-pulling behavior sometimes while the child is studying or watching television or at bedtime. The area of hair loss is usually asymmetric and follows an irregular pattern. Examination of the involved area reveals hair that are broken off at different lengths. There is never the total hair loss of alopecia areata or the scaling and erythema of tinea capitis. In most cases, trichotillomania is evidence of an innocent and benign habit that is best compared to nail biting. However, trichotillomania may sometimes be evidence of more severe emotional distress or a manifestation of obsessive compulsive disorder. In addition, children who swallow their plucked hair may develop a gastric trichobezoar.
Lichen Simplex Chronicus
Lichen simplex chronicus. Hyperpigmented, lichenified plaque with accentuated skin lined caused by repeated rubbing of the area. Lichen simplex chronicus (LSC) is a localized, well-circumscribed area of lichenification (thickened skin) resulting from repeated rubbing, itching, and scratching of the skin. It can occur on normal skin of individuals with atopic, seborrheic, contact dermatitis, or psoriasis.
Varicella-Zoster Virus Infection
Varicella-zoster virus infection: varicella. Multiple, very pruritic, erythematous papules, vesicles (“dewdrops on a rose petal”), and crusted papules on erythematous, edematous bases on the face and neck of a young female. The spectrum of lesions, arising over 7 to 10 days, is typical of varicella.