What Is Subacute Cutaneous Lupus?

Overview

Whether or not you are a pop-culture enthusiast, you may have come across the term “lupus” in the media. Celebrities like Selena Gomez and Lady Gaga have spoken about their battle with it, but what exactly is lupus? Lupus, scientifically known as lupus erythematosus (LE), is an inflammatory connective tissue disorder which is linked to the loss of immune tolerance in the body.¹ This means that the white cells in your immune system start attacking healthy tissues in the body. There are different types of lupus Among them, we have systemic lupus erythematosus (SLE), cutaneous lupus erythematosus (CLE), drug-induced erythematosus and neonatal lupus erythematosus.¹

Types of lupus

1. Systemic lupus erythematosus (SLE)
2. Cutaneous lupus erythematosus (CLE)
3. Drug-induced erythematosus and neonatal lupus erythematosus.¹

The most common types of lupus are SLE and CLE. In the former, your immune system attacks your organs, whereas, in the latter, it attacks your skin, hence the word ‘cutaneous’. Cutaneous lesions form part of the diagnostic criterion for SLE. However, it should be noted that lupus can cause a wide range of cutaneous manifestations, both in the absence of SLE and in combination with systemic involvement, and can be classified as LE-specific and LE-non-specific. ¹

Specific cutaneous manifestations of the disease are called Cutaneous Lupus Erythematosus (CLE), which are split into three subcategories:

Types of CLE

• Acute cutaneous lupus
• Subacute cutaneous lupus
• Chronic cutaneous (discoid) lupus.¹  

This article will explore subcute cutaneous lupus erythematosus (SCLE). In 1977, Gilliam and Sontheimer were the first ones to define and classify SCL.  This subtype is characterised by a photosensitive eruption with the appearance of red annular (ring-shaped) lesions or raised lesions on areas like shoulders, arms, neck and face.¹ 

Causes of subacute cutaneous lupus

SCL is a very complex autoimmune disorder, and so are its causes. It is argued by experts that the development of the disorder is associated with genetic susceptibility, environmental factors and hormones.¹ 

Genetic susceptibility

Recent studies have shown that if you have a family history of autoimmune diseases, especially a type of lupus, there is a higher likelihood of developing  SCL later in life.² 

Drug intake 

Drug intake may also be a cause of SCL. There is also a strong presence of drug-induced SCL, with around 10% to 30% of cases of SCLE being drug-induced. The drugs that have shown an association with drug-induced SCL are antihypertensives, tumour necrosis factor inhibitors, antifungals, proton pump inhibitors and antiepileptics.³ Patients that develop SCL due to drug intake are usually patients that have an older age of onset of the disease rather than patients with idiopathic (a disease or condition which appears spontaneously or for unknown reason) SCL.² It is also important to highlight that cases of drug-induced SCL are usually present during the first couple of weeks to months of drug use. Nevertheless, there have been cases that have been as long as three years.¹  

Environmental factors

Several environmental factors may be associated with SCL such as exposure to ultraviolet (UV) radiation. This can trigger the immune system, causing inflammation and rash on the skin.⁴ Another environmental factor is the exposure to certain chemicals.¹ Smoking and infections are also shown to increase the chances of developing SCL.^1,3

LE is more present among Black or Hispanic people who were assigned females at birth (AFAB), especially in those of childbearing age.⁴ This is because oestrogen levels influence the development of the disease and its symptoms. However, in the case of SCL, Caucasian patients are more at risk.³  

Signs and symptoms of subacute cutaneous lupus

A rash is the main symptom of SCL. As previously mentioned, it appears on areas of the body that are usually exposed to the sun or artificial UV sources such as shoulders, arms, neck and the face.² Although It is very rare, oral lesions have also been reported.³  While the lesions might appear as a ring-shaped rash or a psoriasiform rash, patients typically present mild symptoms of the disease. Although skin lesions usually do not itch or scar, generally there is no induration (thickening).¹ There is the possibility of depigmentation of the affected part.¹ The disease can also cause significant psychological distress.⁵ 

Management and treatment for subacute cutaneous lupus

SCLs can be triggered by different factors and are managed in different ways depending on the gravity of the rash. Physicians may recommend you to:

• Avoid as much as possible exposure to sun and artificial UV sources. It is recommended to abstain from direct exposure to sunlight between 10 am and 4 pm, wear sun-protective clothes and avoid the use of tanning beds.⁵
• Use topical medications which could be corticosteroid cream or calcineurin inhibitors.
• Take oral medications such as hydroxychloroquine, anti-inflammatory drugs, anti-rheumatic drugs or other types of medication that suppress the immune system such as mycophenolate mofetil.⁶ 
• Injections and intravenous therapies such as intravenous immunoglobulin (IVIG).⁷ 

It is important to consult with a healthcare professional about potential treatments for SCL because the treatment must be designed according to the needs and comorbidities of your body. 

Diagnosis

The diagnosis process of this disease has multiple steps: 

1. Diagnosis of lupus: this process consists of a combination of urine and blood tests, identification of symptoms and signs, family history and physical examinations.
2. Dermatologist referral: your physician may transfer you to a doctor who specialises in diseases related to skin, hair and nails.
3. Identification of SCL subtype: your dermatologist will take a small sample of your skin from the affected part to identify which subtype you have.⁷  
4. Your dermatologist will then prepare and further educate you on your personalised treatment plan.

FAQs

How can I prevent subacute cutaneous lupus?

To avoid the progression of skin lesions in SCL, Dermatologists highly recommend avoiding heat, sun and drug intake. The use of sunscreen is essential for patients with this skin disease. It is also important to not manipulate skin lesions, as they can cause new ones.⁷

How common is subacute cutaneous lupus?

SCL is 3 to 4 times more likely to occur in individuals assigned female at birth (AFAB) in comparison to those who were assigned males at birth. It begins mostly during the third or fourth decade of life. In the case of drug-induced rates, the probability is equal in either sex or age according to studies.⁴ SCL rates might vary according to geographical location, due to demographic characteristics. 

Who is at risk of subacute cutaneous lupus?

This autoimmune disorder is strongly linked with a genetic component. As such, individuals at a higher risk have the disease running among their family members. SCL is more common among:

• People assigned female at birth 
• Ages between 20 and 50 
• Individuals with significant ultraviolet (UV) exposure 
• Patients with medication intake, especially blood pressure medication. 
• Presence of other autoimmune diseases, such as rheumatoid arthritis.⁸

When should I see a doctor?

You should seek a doctor if you notice:

• Skin rashes that last more than two days
• Extreme tiredness
• Pain in your joints and muscles
• Other autoimmune diseases such as SLE or rheumatoid arthritis

Summary

SCL is a subtype of cutaneous lupus which is identified by a photosensitive eruption with the appearance of a red ring-shaped rash or raised lesions on areas like shoulders, arms, neck and face. SCLE has multiple probable causes, including genetic predisposition, environmental variables, hormonal fluctuations and drug usage. 

The main symptom of SCLE is skin rash in the form of a ring-shaped or psoriasiform rash. The disease can be prevented and treated through the use of topical, oral, injections and intravenous therapies. Additionally, quitting smoking and limiting UV exposure is essential. The way to diagnose this autoimmune disorder is with a skin biopsy of the affected parts. In the case of undiagnosed lupus, your physician may order several exams before performing a skin biopsy.