This Sunday, we bring to you an article from our archives. Dr. Sanjay Kalra discusses quick practice points for deducing an underlying skin disease in diabetes patients. He elaborates on the primary symptoms and provides a quick treatment guide for tackling common dermatoses, fungal infections, and cutaneous reactions caused due to diabetes treatment.

Diabetes is a multisystemic syndrome, with multifaceted clinical presentations. Cutaneous or skin diseases are a common accompaniment of diabetes. They may be a cause, consequence, or comorbid complaint of hyperglycaemia, and may even result as an adverse reaction to diabetes treatment. The skin is also a mirror to metabolism, and may reveal clues to the aetiology, control, and vascular complications.

Diabetes leading to skin disease

Diabetes is associated with various skin-related symptoms and signs.

1. Generalised pruritis is often noted in persons with diabetes.
2. Acanthosis nigricans, characterised by hyperpigmented, velvety, raised thickening of the skin, is a cutaneous marker of insulin resistance. Common sites include the neck, axillae, elbows, knuckles, thighs and popliteal fossae. Apart from insulin resistance, acanthosis nigricans may be associated with paraneoplastic syndromes, and obesity.
3. Skin tags are also markers of insulin resistance. Sudden onset, or change in the severity of skin tags may signal a worsening of diabetic control. Acanthosis and skin tags occur due to selective resistance to the metabolic actions of insulin, while the mitogenic effects go unchecked. The treatment is good glucose control, with insulin sensitisers such as metformin. Keratolytic agents and cosmetic procedures can be advised as well.
4. Diabetic bullae are small to large, asymmetric non- inflammatory blisters which affect the lower limbs more often. They contain clear fluid, and are self-limiting. They heal without scarring. No specific therapy is available. Coconut oil or other emollients can be prescribed, along with good glucose control.
5. Sclerederma diabeticorum is a symmetrical, non-pitting hardening of the skin due to mucin deposition around collagen bundles. It is most often seen over the back, shoulder and neck. Sclerederma is refractory to treatment, though ultraviolet radiation has been tried.
6. Necrobiosis lipoidica diabetorum (NLD) is a rare granulomatous disease which is pathognomic of diabetes. NLD is variously thought to be due to microangiopathy, immune vasculitis, immunoglobin deposition, abnormal collagen, or other metabolic disturbances. Small shiny papules enlarge to reveal an atrophied or depressed yellow-brown centre. The natural history is variable: the lesions may resolve spontaneously, ulcerate, become painful, or predispose to squamous cell carcinoma. Treatment is unsatisfactory. Intra-lesional steroid can be injected in early phases, and photochemotherapy has been tried.
7. Diabetic dermopathy is a common condition, characterised by non-blanching, small, circumscribed, red or purple maculopapular lesions over the anterior part of the lower limbs. Though asymptomatic, they may cause distress to the patient. There is no specific treatment for this condition.

Infections associated with diabetes

1. Skin and soft tissue infections are a common feature of uncontrolled diabetes, especially in tropical climates. Furuncles and carbuncles may occur anywhere on the body, with Staphylococcus aureus being the most frequently isolated pathogen.
2. Fungal infections can also affect any part of the body. Tinea corporis, Tinea capitis, Tinea cruris, Tinea pedis and Tinea unguum can occur; Trichophyton rubrum, T. mentagrophytes var interdigitale, and Epidermophyton floccosum too.

Fungal infections are a cause of refractory diabetes and must be actively sought as part of clinical assessment. Topical and oral antifungal agents can be used. Another fungal infection which is associated with poor control is vulvovaginal candidiasis, which presents as pruritis vulvae. Good glucose control is necessary, along with antifungal therapy, to treat this. Often, broad spectrum therapy to cover Trichomonas vaginitis may be necessary as well.

Skin disease due to diabetes treatment

Modern, glucose-lowering drugs are rarely implicated in cutaneous reactions. However, dipeptidyl peptidase-4 inhibitions (DPP4i) are known to cause skin lesions, and should be stopped if a drug-induced reaction is suspected. Insulin usage with improper technique, can lead to local site reactions such as bleeding and bruising, pain, and lipohypertrophy. Allergic reactions are extremely rare with modern insulins and may be immediate, delayed or biphasic. Oedema may occur due to fluid retention in persons with poor control who are started on insulin. Focal vitiligo and hyperpigmentation (tattooing) have been reported at sites of insulin administration.

Common dermatoses

Various other dermatoses are found frequently in persons with diabetes.

• Vitiligo, which presents as depigmentation around the mouth or eyes, or over the extensor aspects of extremities, is associated with type 1 diabetes, and is a marker of autoimmunity
• Lichen planus, is a multifactorial disorder which presents as white stripes over the oral mucosa
• Perforation dermatoses, such as perforating collagenosis and perforating folliculitis, are frequently seen in chronic renal failure; they present as papules over extensor surfaces, and are due to a combination of metabolic derangements, vasculopathy and infection
• Eruptive xanthomas are large, firm, yellowish papules that occur on extensor surfaces; they are a marker of hyperlipidaemia, and respond to glucose-lowering therapy
• Xanthelasmae are smaller lipid deposits, usually seen near the eyelids and medial aspect of the eyes
• Psoriasis is a multifactorial, immune disease characterised by reddish plaques with silvery scales, usually over the scalp, knees, elbows or lower back; vitamin D deficiency is associated with these lesions
• Bullous pemphigoid, dermatitis herpetiformis and Kaposi’s sarcoma are some well-defined skin disorders that may be associated with diabetes

Summary

The skin is associated with diabetes in multiple ways. Inspection of the skin can reveal clues regarding the pathogenesis or type of diabetes, the level of control, and the reasons for poor control.

To read other articles in this series, click,

Difficult diabetes- The diagnosis is important

Hyperglycemia- Think beyond glucose

Diabetes and the liver- Why this vicious circle needs immediate attention

This article was originally published on December 17, 2020.

Disclaimer- The views and opinions expressed in the article and videos are those of the speakers and do not necessarily reflect the official policy or position of M3 India.

The author, Dr. Sanjay Kalra is a leading Endocrinologist and the current President of the Endocrine Society of India.