There are no official guidelines to assist in answering this question. I will search for relevant research papers instead.
From the Research
Scleroderma Skin Biopsy Findings
- The skin biopsy findings in scleroderma patients show a depletion of elastic fibers in the papillary dermis and disorders of the network in the reticular dermis, such as their absence in the skin blood vessels walls 1.
- The reticular fibers are absent in the papillary dermis, and the reaction in the reticular dermis structure is variable from one case to another 1.
- There is a gathering of glycosaminoglycans in the superficial papillary dermis, heterogeneity of collagen fibers, and a decrease of mast cells in the dermis 1.
- The skin biopsy can also show mucinous material in the dermis and proliferation of fibroblasts accompanied by mild dermal sclerosis, as seen in scleromyxedema, a possible disease entity in the differential diagnosis of scleroderma 2.
- Histologically, systemic scleroderma and localized scleroderma (morphea) show comparable changes on skin biopsy specimens, with inflammation and sclerosis of the skin, the primary difference being the depth at which these changes occur 3.
- Proteomic analysis of paired skin biopsy samples from affected and unaffected areas of the same patient has identified approximately 2000 non-redundant proteins, with 169 proteins significantly differentially expressed in affected versus unaffected tissues 4.
- Pathway analyses have shown that these proteins are involved in multiple pathways associated with autoimmune diseases and fibrosis, and five proteins have been confirmed to be significantly differentially expressed in scleroderma affected versus unaffected skin biopsies, potentially serving as biomarkers for the disease 4.