Pigmented purpura in 12-year old

  My 12-year old grandson has been diagnosed with "Mojacchi-Shaumberg disease"  He has a pigmented purpura on his legs.  A biopsy was performed which came back negative.  The problem is that he is very self- consious about the lesions when he has to wear shorts in gym class.  The doctors are interested in his case, and told my daughter that "this is usually found in older men".  She asked me to contact you to see if you have any further information or suggestioons as how to find more.
Subject : Pigmented Purpura
Thank you for your request .
" Mojacchi - schamberg disease" is one of several distinct pigmented lesions set under the heading of       " Pigmentary Purpuric Eruptions" . Some textbooks divide it into two distinct types :
1. Purpura Annularis Telangiectodes of Mojacchi
2. Schamberg's Progressive Pigmented Purpuric Dermatosis
Long titles or names are common in dermatology , giving you a brief description of the lesion . Let me help you through these two names :
PURPURA - which is the cardinal feature of M-S disease , is a term used to describe a discoloration resulting from a tiny bleed in the skin or slightly deeper.
TELANGIECTASIA- describes the smallest blood vessels in the skin when they become visible to the eye.
ANNULARE- describes lesions in circular arrangements
Both pigmented lesions are similar in being located on the lower legs , but may spread up the thighs and trunk. They are seen in young adult men but several cases have been reported in the pediatric age group.
No definite cause has been found . The basic pathology is enough inflammation around the tiny blood vessels in the skin ( called capillaries) that makes them break down and bleed into the skin . The amount of bleeding has no serious consequences except for the skin discoloration . A lesion may fade away within a year but relapses are common . There is no definite treatment .
I suggest discussing your grandson's concerns with his dermatologist , he /she may have other alternatives to cover up the exposed lesions depending on their size and location.
I hope this gives you a better idea on the disease . I'm including a few references that may help you further in your search .
1. Rasmussen.JE -  J Am Acad Dermatol.  1982 ;6 :67-72
2. Aiba S ,et al -  Arch Dermatol.  1988 , 124 :1058
3. Templetoin HJ -Arch Dermatol & Syph. ;16 : 141,  1927
4. Randall SJ , et al -  Arch Dermatol.  1951 ; 64 : 177.
5. Nichamin SJ , Brough AJ -  Am J Dse Child.  1968 ; 116 : 429
6. Newton RC , Raimer SS - Dermatologic Clinics  1985 Jan ; 3(1) : 165-169
  
This information is for academic purposes only and the ultimate decision for care and management should be decided with the patient's physician
Thank you
LM