Infant Leg Rash

[chill68]

My 5 month old son has had a recurring lower leg rash which has doctors here perplexed.  It has occured now 4 times since the age of 3 months.  It consists of red blotches that appear to be under the surface of the skin.  It lasts approximately 4 to 5 days before fading to almost nothing or in some cases absolutely nothing.  The third time it occured we took him to the hospital here as the sole of his foot went blue also.  Initial diagnosis was of a venous hemangioma but this was ruled out after an ultrasound revealed no growths beneath the epidermis.  A blood test showed normal platelet and white blood cell counts.  At no stage has our boy shown any discomfort from the marks but the continued reappearance has us worried.  Could it simply be a type of heat rash, he never gets it anywhere else on his body, just his left lower leg.

[Alan Rockoff, MD]

I must apologize, but your description does not remind me of any skin conditions I'm familiar with.  I can't imagine that these vascular changes have any medical significance, however.  I would just have your doctors keep an eye on it.  Little kids sometimes have blood vessels that open and close more rapidly than they do in older people.  If so, your son's color changes may well subside over time.

Take care.

Dr. Rockoff

[taminj]

My 5 month old son has eerily similar symptoms to chill68's son. He has a recurring knee and lower leg rash which a doctor labeled as petechiae. He has not exhibited any other symptoms. He first developed these pinprick-sized dots on his right leg a month ago when he was 4 months. At the same time his father and brother had cold symptoms. A few days later the rash appeared on his left leg and began fading from his right leg. My baby never developed cold symptoms at that time. I took him to our local pediatrician who said he had never seen anything like his rash. He then referred me to a pediatric dermatologist, who also was baffled, and ordered bloodwork. His blood cell counts and platelets were normal with some abnormally shaped cells indicating a virus, in the doctors opinion. The week following the doctors visit, all petechiae disappeared. The next week they reappeared only on his left leg. He then came down with cold symptoms, and the petechiae since have not faded. The pediatric dermatologist has seen other children in my area suddenly with similar symptoms, but she is assuming the cause is viral with the older kids.(we live in northern NJ) However, since my baby is so young she wants to do a biopsy which could leave a 3mm scar on his leg. We are going for  a second opinion before proceeding. Is this biopsy necessary if he is asymptomatic otherwise? Is it ok to conclude the cause is viral and wait and see? Is there a different type of doctor to consult other than a dermatologist for a different perspective?