After chest wall skin, shoulder area is the second most common area of the skin to develop keloids. The most common triggering factor for development of keloids in shoulder area is acne, whereby the inflammatory reaction of the skin triggers keloid formation in those who are genetically prone. Next to acne, skin injury from vaccinations in deltoid area is another common triggering factor in formation of keloids in this area. Direct injury to shoulder skin, although uncommon, may also result in formation of keloid in this area. This is more often due to attempts to surgically remove an existing shoulder keloid.
In their early stages, shoulder keloids in all races, like all other keloids, start as a papule or a small linear lesion that often grows to reach a certain size before patients present for medical care. Depending on the intensity of the disorder, and its genetics, and with passage of time, should keloid lesions will grow in size, expand and often merge with other nearby lesions. The pace of growth and extent of the skin involvement is simply driven by the underlying genetics of the disorder. Those with mild form of the disorder develop very few keloid lesions, and their lesions remain small. Those with more severe from of the disorder, develop numerous keloid lesions, that grow large in a short period of time.
Like keloids in other parts of the skin, certain types of shoulder keloids are race or gender specific. Large tumoral forms of shoulder keloids are exclusively seen in Africans, African Americans and those with black skin.
Pure linear shoulder keloids are quite uncommon. Patients with mild form of the illness may present either with one or few small papular or mixture of papular and linear lesions and with passage of time, skin involvement will remain limited to one or a few lesions.
In those with more severe form of the illness, keloid lesions grow and enlarge over time, and merge with each other to form larger lesions that may spread and cover a wider area. It is important to keep in mind that the clinical presentation and appearance of the disorder is driven by its genetics which controls the pace of progression of the illness over time.
More severe form of this disorder leads to formation of very large and often bulky keloidal lesions that tend to involve large areas of skin and grow and spread with a rapid pace to form large tumors or wide patches of the disorder. This pattern of growth is often race specific and limited to Africans and those with dark and black skin. The most severe forms of shoulder keloids are not only race specific, but also gender specific and predominantly seen among Africans/African American females.
Surgical excision of shoulder keloids often results in worsening of these keloids, with the worst cases seen among those who have had several attempts at removing their keliod(s). Here again, contrary to the common belief and practice of some physicians, keloids should not be removed surgically. Primary shoulder keloids should only be treated with non-surgical, i.e. medical means such as cryotherapy as well as intra-lesional steroids or chemotherapy drugs. Medical treatment of recurrent and secondary shoulder keloids can become quite complicated and rather challenging.