Section 22: Panniculopathies

Subcutaneous fat necrosis of the newborn This is a self-resolving and benign condition that is seen in healthy newborns. The etiology of this disorder is probably ischemic injury to subcutaneous fat. Lesions often develop at sites of pressure.

The infants develop single or multiple firm red-purple nodules or plaques that are asymptomatic. Cheeks, back, buttocks, and thighs are the most common locations. It is difficult to capture the quality of panniculitis in the figure, but a sense of it can be appreciated on the back of the patient pictured in Fig. 22-2.

Subcutaneous fat necrosis Lesions may be present at birth, or they may develop during the first month of life. Most lesions resolve spontaneously over a period of 2 to 4 weeks, but some last significantly longer. There is usually no residual atrophy or scarring. Subcutaneous fat necrosis is occasionally associated with hypercalcemia, as was the case in this patient.

Sclerema neonatorum Unlike the condition just described, sclerema neonatorum presents itself as symmetrical areas of induration on cheeks, shoulders, buttocks, and calves. The skin over involved subcutaneous fat is uniformly board-like, cold, and livid in color, as though frozen. Infants so affected appear rigid because mobility is interfered with by the sclerema and they are severely ill. Mortality is high. The condition is more common in premature infants and in those with severe underlying disease, such as sepsis or dehydration.

Erythema nodosum This condition, characterized by red, tender, subcutaneous nodules on the extensor aspects of the legs between knees and ankles has numerous causes. The most important conditions are 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 etiology can be found.

Panniculitis from cold Local exposure to cold leads to the formation of ice crystals within cells. Injury to cell contents occurs during both cooling and thawing. Cold panniculitis may occur in a child whose glove or boot has filled with snow. The patient shown in Fig. 22-7 was out in freezing weather with a strap ...