Lupus erythematosus subacute-cutaneous L93.1

Sontheimer, 1979

Independent, photosensitive (photosensitivity is expected in about 80% of patients - Black et al. 2002) subgroup of cutaneous lupus erythematosus with relapsing activity and occurrence of disseminated, red, mostly blurred, homogeneously disc-shaped, but also anular, saturated red plaques, which occur preferentially in light-exposed skin areas.

The light-relatedness results from the "macro-pattern", which more often (not always) leaves out non-UV-exposed skin areas (note: there is not always a temporal relationship between the appearance of the skin changes and the previous UV exposure, which may have occurred months before).

There is a higher risk of systemic involvement than in the chronic discoid variant(lupus erythematosus chronicus discoides).

In elderly patients, SCLE may be associated with malignancies (paraneoplastic subacute cutaneous lupus erythematosus), with non-Hodgkin's lymphoma and carcinoma of the solid organs most commonly observed (Lazar AL 2022).

Sun exposure. There is varying degrees of UV sensitivity.

Drugs are thought to be the trigger in about 25-30%. Possibly due to abnormalities in drug metabolism (polymorphism of hepatic acetyltransferase, slow acetylators) or they are drugs that are photosensitizing per se.

The following drugs have been described in association with the initiation or exacerbation of SCLE: nonsteroidal anti-inflammatory drugs (e.g., piroxicam), tetracyclines, antifungals(griseofulvin; terbinafine), antihypertensives (captopril, cilazapril, hydrochlorothiazide), proton pump inhibitors.

Also described is occurrence after ingestion of spironolactone, cinnarizine, D-penicillamine, interferon beta, ranitidine, antidiabetics(sulfonylureas), doxorubicin, docetaxel, carboplatin (see below cytostatics, extravasates).

Pathogenetically relevant appears an increased susceptibility in the presence of HLA types B8, DR2, DR3, DQw2, DRw52.

Predominantly affects fair-skinned (Caucasian) women; initial manifestation between 30-50 years of age.

Light-exposed areas: face (leaving out the mid-face and periorbicular region rather), upper thorax, arms.

Integument: Acute, chronically active, multiple or numerous, disseminated, sharply or also indistinctly circumscribed, 0.2-5.0 cm in size (rarely > 10.0 cm), disc-shaped, anular or gyrated, red also red-brown spots or plaques with a smooth but also crusty surface. Blistering is possible.

Erythema multiforme-like skin lesions are also possible. In these cases, clinical differentiation from Rowell's syndrome is difficult.

Characteristic are (temporarily persistent) hypopigmentation (more rarely hyperpigmentation) after healing of the lesions.

Extracutaneous manifestations:

• renal (16%)
• hematologic pathology (8%)
• minor visceral involvement with polyarthritis, serositis (1%)
• less frequent are cerebrovascular erscehinungen.
• The clinical picture of drug-induced SCLE is identical, but usually in the form of disseminated exanthema. Triggers are mainly hydrochlorothiazide, terbinafine, proton pump inhibitors. There are also known cases of drug-induced SCLE caused by angiotensin-converting enzyme (ACE) inhibitors, allylamine antifungals, calcium channel blockers, anticonvulsants, antimicrobials, gemcitabine, and aromatase inhibitors (anastrozole).

At 75% higher titre ANA, more rarely anti-DNA antibodies. Particularly characteristic is the detection of anti-SSA/Ro-antibody (about 50% of cases) and anti-SSB/La-antibody. Possibly leukopenia (cytopenia), hypergammaglobulinemia.

Basically as in cutaneous lupus erythematosus, but less marked hyperkeratosis. Atrophic epithelium, orthokeratosis, vacuolar degeneration of basal epithelial cells, civatte-bodies (interface dermatitis). Profuse dermal edema with mucin deposition, dense perivascularly oriented lymphocytic infiltrate.

The diagnosis of subacute cutaneous lupus erythematosus lupus erythematosus is based on the patient's history, clinical presentation, laboratory tests, and skin biopsy specimens.

External glucocorticoids (e.g. Dermatop) are only moderately successful. Light protection is important - both in the UVB and UVA range!

Initial glucocorticoids such as prednisone (e.g. Decortin) 20-40 mg/day p.o., possibly higher doses. Alternatively cloprednol (Syntestan) 10-15 mg/day. Reduce dosage depending on clinic. This treatment approach can bridge an exanthematous acute situation well.

Antimalarials should be the first choice for systemic therapy e.g. chloroquine start with 250 mg/day, after 2-4 weeks reduce to 250 mg every 2nd day).

Thalidomide and lenalidomide, systemic retinoids, dapsone, and methotrexate represent second-line options in selected cases.

Third-line therapeutic options include mycophenolate mofetil and other immunosuppressive drugs.

The monoclonal antibody belimumab, which targets soluble human B-cell activating factor, is a fourth-choice treatment for refractory cases.

Quoad vitam favorable. Chronic course is characteristic.

Skin lesions usually heal completely and without scarring. Hypo- or hyperpimgentations are possible.

More than 50% of patients are positive for more than 4 ARA criteria (see lupus erythematosus, systemic).

About 15% of patients develop internal involvement (arthralgias, nephritis, cardiac involvement, hematologic complications) during the course of their disease and fulfill the criteria of systemic lupus erythematosus.

There are several authors who classify subacute cutaneous lupus erythematosus as a facultative paraneoplastic dermatosis. SCLE patients should undergo smit thorough cancer screening to rule out underlying malignancy with a clinically silent evolution (Lazar AL 2022).

1. Amato L et al (2003) Subacute cutaneous lupus erythematosus in childhood. Pediatr Dermatol 20: 31-34
2. Black DR et al (2002) Frequency and severity of systemic disease in patients with subacute cutaneous lupus erythematosus. Arch Dermatol 138: 1175-1178
3. Bottomley WW et al (1995) Methotrexate for the treatment of severe mucocutaneous lupus erythematosus. Br J Dermatol 133: 311-314.
4. Callen JD (2009) Clinically relevant information about cutaneous lupus erythematosus. Arch Dermatol 145: 316-319
5. Farhi D et al (2006) Terbinafine-iduced subacute cutaneous lupus erythematosus. Dermatology 212: 59-64
6. García AG et al (2014) Subacute cutaneous lupus erythematosus associated with pemetrexed plus carboplatin chemotherapy. J Clin Rheumatol 20:449-450
7. Khokher W et al (2022) Subacute cutaneous lupus as a paraneoplastic manifestation of non-Hodgkin lymphoma. J Investig Med High Impact Case Rep 10:23247096211063066.
8. Lazar AL (2022) Subacute cutaneous lupus erythematosus: A facultative paraneoplastic dermatosis. Clin Dermatol 40:728-742.
9. Mutasim DF (2003) Severe subacute cutaneous lupus erythematosus presenting with generalized erythroderma and bullae. J Am Acad Dermatol 48: 947-949.
10. Pramatarov K et al (2000) Subacute cutaneous lupus erythematosus presenting with generalized poikiloderma. J Am Acad Dermatol 42: 286-288.
11. Sontheimer RD et al (1979) Subacute cutaneous lupus erythematosus: a cutaneous marker for a distinct lupus erythematosus subset. Arch Dermatol 115: 1409-1415
12. Wollenberg A et al (1991) Thiazide diuretic-induced subacute cutaneous lupus erythematosus. Dermatol 42: 709-712
13. Tebbe B et al (1994) Course and prognosis of subacute cutaneous lupus erythematosus. A prospective study of 34 patients. Dermatologist 45: 690-695
14. Wollina U et al (1989) On the spectrum of dermatologic manifestations in patients with subacute cutaneous lupus erythematosus and their nosologic significance. Akt Dermatol 15: 208-212