Erythema nodosum. Red, tender, subcutaneous nodules on the extensor aspects of the legs between knees and ankles are a common condition of many causes, some clear, some likely, and many obscure. The most important conditions that are heralded or attended by erythema nodosum are such infections as streptococcal upper-respiratory infections, ulcerative colitis, histoplasmosis, coccidioidomycosis, tuberculosis, syphilis, and leprosy. Another condition that is sometimes revealed by investigation of erythema nodosum is sarcoidosis. Drugs, including oral contraceptives, appear to be the cause of particular cases of erythema nodosum. In many cases, however, no clear cause can be found.
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.
Port-Wine Stain after Laser Treatment
Marked resolution of the port-wine stain after multiple treatments with pulsed dye laser.
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.
Infectious mononucleosis. Marked white exudate on the tonsils of a child with infectious mononucleosis.
White Bumps (Milia)
Little white bumps on the nose and face ("milia") are caused by blocked oil glands. When baby's oil glands enlarge and open up in a few days or weeks, the white bumps disappear.
Vascular Malformations on Foot
Vascular malformations. These are congenital malformations that consist of capillary, venous, arterial, or lymphatic abnormalities. There are often combined alformations that comprise different types of vessels. Examples of vascular malformations include port-wine stains (capillary malformation), cystic hygroma (lymphatic malformation), and venous malformations. Vascular malformations are present at birth and grow proportionately with the child. Some vascular malformations may not manifest themselves until adolescence or adulthood. These figures represent venous malformations on the hand and foot.
Dysplastic Nevi (Atypical Moles)
Dysplastic nevi are moles that are larger than average (larger than a pencil eraser) and irregular in shape. They tend to have uneven color with dark brown centers and lighter, uneven edges.
Clubbed nails. Increased curvature of the nail plate may be due to a wide variety of causes. In this patient, the large, convex nails are a hereditary anomaly and were found to be present in both father and brother. Other causes of clubbing of the nails in children include cyanotic congenital heart disease, cystic fibrosis, and chronic inflammatory bowel disease.
Furuncle: S. Aureus
Furuncle: S. aureus. Soft-tissue swelling of the forehead with central abscess formation, nearing rupture.