(Recurrent summer eruption; Hydroa puerporum; Hydroa aestivale)
Definition. A recurrent, vesicular and scar-producing affection of childhood, occurring chiefly in the summer.
Symptoms. The eruption usually develops in the summer months, appearing in crops and on exposed surfaces, especially the face, and ceasing at the onset of cold weather. It usually begins in the first few years of life and tends to disappear as puberty develops. The lesions consist of erythematous spots, on which develop small or large vesicles, singly or grouped. These become umbilicated, dried and, when the crusts fall off, leave depressed scars. It is possible that extensive scarring may be thus produced. Occasionally, the process is arrested the eruption, and itching and burning may attend it. Though fresh crops may prolong the duration even into the winter in exceptional cases, the average attack runs a course of two or three weeks.
Etiology and Pathology. The etiology is only indicated by its occurrences in childhood, especially among boys, and from exposure to heat or cold, indicating that vasomotor disturbance may be causative. Pathologically, the process is an inflammation of the epidermis and corium, followed by the formation of vesicles in the epidermis and finally by necrosis.
Diagnosis. The age of the patient, exposed location of the eruption, and recurrences under certain conditions during the period of youth should diagnose the disease from dermatitis venenata, dermatitis herpetiformis, pemphigus, or erythema multiforme.
Prognosis and Treatment. The disease tends to disappear spontaneously at or about puberty. Treatment is generally unsatisfactory. Mild applications of carbolic acid or calamin may be used to relieve the subjective sensations. The exposed surface should be protected from the sum and wind. The remedies suggested for erythema multiforme might the studied.