Impetigo herpetiformis L40.1

Historical term for a rare variant of pustular psoriasis pustulosa generalisata. Clinically, a generalised pustular clinical picture is present, which is interpreted as a clinical manifestation of a previously latent or de novo developing pustular pustular disease in pregnancy.

Unknown; discussed is a parathyroid hormone insufficiency with hypocalcaemia in pregnancy or surgical damage to the epithelial corpuscles. The pathogenetic significant influence of pregnancy becomes obvious, as healing usually occurs after pregnancy.

In individual cases a mutation of the IL36RN gene has been reported.

By definition, the disease only occurs in pregnant women; age: 20-40 years; mainly in the 2nd half of pregnancy. A recurrence is possible with each further pregnancy.

A manifestation can also occur outside of the pregnancy.

Acute onset with severe impairment of the general condition, with pronounced feeling of illness, fever, chills, possibly diarrhoea.

On the integument bent exanthema with highly red, large erythema and plaques.

After a few days, disseminated or grouped, 0.1-0.2 cm large, white, bizarrely limited (not follicular) pustules develop on these flat lesions, initially single, later confluent to larger "pus lakes".

The formation of anular figures is possible. Healing with formation of inwardly directed collerette-like scaly margins.

Occurrence of erythroderma is possible.

Symptoms of hypocalcaemia may appear (low serum calcium, tetany, Chvostek's sign).

This very rare pregnancy dermatosis is associated with the highest risk for the pregnant woman compared to other pregnancy dermatoses.

Dysproteinemia; leucocytosis; neutrophilia; iron deficiency with anemia; decreased serum calcium; decreased Vit D3 levels; significantly accelerated SPA; CRP is elevated.

Dehydrating measures. Application of ethanolic zinc oxide shaking mixture or dye brushes, e.g. with potassium permanganate (light pink) or methylrosanilinium chloride solution (gentian violet) to avoid secondary infections.

In addition, topical glucocorticoids such as 0.1% triamcinolone cream, 0.25% prednicarbate (e.g. Dermatop cream), 0.1% mometasone (e.g. Ecural fat cream) for improved healing of the skin as well as in case of highly inflammatory components.

In the foreground is the substitution of parathyroid hormone with dihydrotachysterol (eye drops 10) and calcium replacement according to blood level (for tetany: 20 ml calcium solution 10%).

Caution! Digitized patients!

Usually glucocorticoids are administered additionally in medium dosages such as prednisolone 60-80 mg/day (e.g. Decortin H).

For long-term treatment vitamin D and calcium p.o. The use of ACTH (e.g. Synacten) is also possible.

Close monitoring of hormone status, calcium level, iron and protein balance! Monitoring with regard to secondary infections!

Causitic messages exist about success with Secukinumab (Chhabra G et al. 2019).

1. Chhabra G et al (2019) Impetigo herpetiformis responsive to secukinumab. Dermatol Ther 32:e13040.
2. Chang SE (2003) Impetigo herpetiformis followed by generalized pustular psoriasis: more evidence of same disease entity. Int J Dermatol 42: 754-755
3. Kaposi M (1887) Impetigo herpetiformis. Arch Dermatol Syphil 19: 273-296
4. Renner R et al (2010) chronic inflammatory and autoimmune mediated dermatoses in pregnancy. dermatologist 61: 1021-1026
5. Gao QQ et al (2013) Impetigo Herpetiformis during pregnancy: a case report and literature review. Dermatology 226: 35-40
6. Soutou B et al (2015) Skin disease in pregnancy. Best Pract Res Clin Obstetr Gynaecol 29: 732-740
7. Sugiura K et al (2014) IL36RN mutations underlie impetigo herpetiformis. J Invest Dermatol 134:2472-2474
8. Weiseseel P et al. (2016) Pustular psoriasis. Dermatologist 67: 445-453