Diabetic skin also ages faster due to inflammation triggered by both intrinsic and extrinsic factors. In diabetic skin in vitro studies showed elevated levels of MMP-1 and MMP-2, increased lysyl oxidase (LOX) expression, higher cross-linked collagens and fragmented collagen fibrils compared to healthy skin. It is thought that deterioration of dermal collagen structural integrity and mechanical properties occurs at an earlier age in those with diabetes.12 Mechanisms that alter skin surface integrity have been identified for various skin conditions that present with dry skin.6,7,13-15The formation of the SC barrier, specifically generation of its lipophilic components, involves several pH-dependent enzymes.7Two key lipid-processing enzymes, β-glucocerebrosidase and acid sphingomyelinase, have pH optima of 5.6 and 4.5, respectively, as part of the skin’s acid mantle. They are involved in the synthesis of ceramides––critical components of the per- meability barrier.7 Activity of β-glucocerebrosidase is 10 times lower in situ at pH 7.4 than at pH 5.5. The processing of lipids secreted by lamellar bodies and the formation of lamellar struc- tures require an acidic environment.7 Skin ConditionsThat May Benefit from Skin Cleanser and Moisturizer Use
Examples of common skin changes in DM that may benefit from gentle skin cleansers and moisturizers are, diabetic foot syndrome (DFS), ichthyosiform skin changes, and xerosis due to diabetes, and keratosis pilaris.
Acanthosis nigricans is mentioned as an example of a condition that may benefit from gentle skin cleansers and moisturizer use as an adjunctive measure together with treatment of the under- lying condition, for example, insulin resistance.
Acanthosis Nigricans
Acanthosis nigricans (AN) presents with multiple poorly de- marcated plaques with grey to dark-brown hyperpigmentation and a thickened velvety to verrucous texture. In insulin resistant states the proposed mechanism is stimulation of IGF-1 receptors in the skin by cross-reaction with insulin.16,17 Common locations for AN are posterior neck, axilla, elbows, palms, inframammary creases, umbilicus, and groin; it is typically asymptomatic.16,17
Management of AN includes lifestyle changes such as dietary modifications, increased physical activity, and weight reduction. While AN can occur in other settings, in patients with DM, medi- cation such as metformin may be recommended to improve glycemic control and reduce insulin resistance, although conclusive evidence to support this is lacking. are usually ineffective in patients with generalized involvement of the condition. In those with thickened or macerated areas of skin, topical keratolytics such as ammonium lactate, retinoic acid, or salicylic acid can improve appearance of AN.16,17
Diabetic Foot Syndrome
Diabetic foot syndrome (DFS) is a broad term denoting anatom- ic and physiologic changes in the feet resulting from DM.1,4,5The incidence and prevalence of DFS is reported at 1% to 4%, and 4% to 10%, respectively.1 DFS is slightly more prevalent in type 1 DM compared with type 2 DM.1
Diabetic foot ulcer (DFU), the end stage of DFS, is a global pan- demic of diabetes, developing countries are especially on the frontline (Figure 1).4 Persons with DM have a 15–25% lifetime risk of DFU, and have a 50–70% recurrence rate within 5 years.4,5 Depending on size, duration and depth, healing can be difficult and take, on average, 11–14 weeks to heal.They precede ampu- tation in 85% of cases, with a 1-year amputation rate estimated at 15%.4,5 DFS and DFUs profoundly impact costs to the health system.4,5
DFS presents initially with callosities and dry skin related to diabetic neuropathy.4,5 In later stages, chronic ulcers and a variety of other malformations of the feet may develop.4,5 DFUs frequently present with secondary infection, diabetic neuro-os- teoarthropathy and clawing deformity (Figure 2).4,5 Neuropathic, but mostly painless, ulceration results from peripheral neuropathy, and is the most common type of complication. However, ulceration may be due to either ischemic changes or due to both peripheral neuropathic and ischemic disease.4,5 Dry skin of the diabetic foot is mostly due to the autonomic component of the peripheral neuropathy that may be present.4,5
The interdisciplinary, team-based approach to DFU should in-
