Galli-galli diseaseQ82.8

Up to now only rarely described (14 contributions known, but certainly more frequently occurring), autosomal dominant inherited genodermatosis with reticular hyperpigmentation of the flexures, which belongs to the spectrum of reticular pigment dermatoses. Probably acantholytic variant of M. Dowling-Degos. The eponym Galli-Galli is derived from the brothers F. and W. Galli with whom the disease was first described.

A "loss of function mutation" in the KRT5 gene was detected (as in Dowling-Degos disease). It is suspected that this mutation leads to a loss of adhesion of the keratinocytes, possibly also to a disturbance of the melanosome distribution (see histology).

First signs of skin symptoms between the 40th and 60th year of life.

Overall rather monomorphic clinical picture with spot-like, partly also confluent, also net-like hyperpigmentations with emphasis on flexures and intertrigines. Also localized on the chin, neck or back of the neck. In addition, disseminated, lenticular, reddish-brown, scaly papules and plaques on the neck, trunk and proximal extremities have also been described. 1 case of "segmental" distribution of skin lesions has been described.

Acanthosis nigricans; Papillomatosis confluens et reticularis; Pemphigus chronicus benignus familiaris; Transitory acantholytic dermatosis; Urticaria pigmentosa, Dowling-Degos disease.

Remember! The mutation in the KRT5 gene has already been described in Dowling-Degos disease. This supports the thesis that these are different variants of the same disease. Whether other diseases from the form of reticular hyperpigmentation such as:

• Erythromelanosis follicularis faciei et colli (Kitamura disease)
• Haber syndrome
• Dyschromatosis symmetrica hereditaria (Dohi disease)

are separate entities, or variants of this mutation will be discovered in the future.

1. Arnold AW et al(2012) Type 1 segmental Galli-Galli disease resulting from a previously unreported keratin 5 mutation. J Invest Dermatol132:2100-2103
2. Bardach H et al (1982) Genodermatosis in a pair of brothers: Dowling-Degos, Grover, Darier, Hailey-Hailey or Galli-Galli disease? dermatologist 33: 378-383
3. Braun-Falco M et al (2001) Galli-Galli disease: an unrecognized entity or an acantholytic variant of Dowling-Degos disease? J Am Acad Dermatol 45: 760-763

4. Hanneken S et al (2011) Galli-Galli disease. Clinical and histopathologicalinvestigation
   using a case series of 18 patients. Dermatologist 62:842-851

5. Mota R et al (2010) Classical and atypical presentation of Galli-Galli disease. Dermatologist 61: 284-286
6. Klingmüller G (1986) The M. Galli-Galli - an entity? Nude Dermatol 12: 41- 45

7. Schmieder A et al (2012) Galli-Galli disease is an acantholytic variant of Dowling-Degos disease: additional genetic evidence in a German family. J Am Acad Dermatol 66:e250-251