ScarL90.5

Scar classification according to Mustoe (varied here)

• Maturescar (light, flat scar at the skin level or slightly below the skin level)
• Immaturescar (red, sometimes itchy and rarely slightly painful papule or plaque, minimally raised)
• Linear hypertrophic scar (red, raised, sometimes itchy and slightly painful scar, growth 3-6 months, then regression over 2 years)
• Areal hypertrophic scar (> 0.5 cm, red, irregularly raised, also nodular, marked itching and pain to touch, occasionally spontaneous pain; initial wound margins are respected)
• Atrophic scar: pale, often multiple skin depressions, also narrow deep (ice pick), or wide cup-shaped (rolling), or wide like punched out (boxcar) depressions
• Small keloid (red, irregular surface level, also nodular, always itching and highly sensitive pain to touch, spontaneous pain; initial wound margins are exceeded)
• Large keloid (> 0.5 cm, red, irregular surface level, plaque-like also nodular, also irregularly mounded, always itching and highly sensitive pain on touch, spontaneous pain frequent; continuous growth over 1 year. Initial wound edges are exceeded).

Scars develop as a repair defect of the collagen network of the reticular dermis and possibly also of the subcutaneous adipose tissue after trauma, due to a necrotizing inflammation or (rarely) due to a malformation.

Scarring is observed, for example, in response to mechanical action, especially on previously damaged skin (e.g., damage from corticosteroids [steroid skin] or senile involution). However, scars may also develop in inflammatory or infectious diseases when the disease process itself leads to destruction of the dermal connective tissue and/or destruction of the skin appendages. Typical examples of this are chronic discoid lupus erythematosus or lupus vulgaris.

The epidermis in a scar appears thinned and folded like cigarette paper in its atrophic final state, the skin surface is flat or deeply sunken. A scarring of the fatty tissue is visible as a trough-shaped indentation. Scars are mechanically less resilient and also less tear-resistant.

In their final state they are lighter in colour than their surroundings (loss of melanocytes), less often hyperpigmented (dark-skinned people).

Occasionally, spatter-like or bizarrely linear pigmentation may occur in a scar surface. These usually start at the edge of the scar (in the case of persistent follicular structures, repigmentation in the centre of a scar can also start from these) and are to be seen as an attempt to repigment the pigment-less scar.

Hypertrophic scars or scar keloids present as rough exophytic papules, plaques or rough nodes.

Scars can also grow out as coarse connective tissue strands, which may lead to restrictions of movement that should be prevented as far as possible.

Mature healed scar: Vessels and epidermis thickness are reduced in the area of the scar. The dermis usually shows an accumulation of fibroblasts of varying density, parallel to the surface. Inflammation parameters are missing. Skin field, follicle orifices, papillary relief, elastic fibres, hair and skin glands are reduced or missing completely.

1. Aschoff R (2014) Therapy of hypertrophic scars and keloids. Dermatologist 65: 1067-1077
2. Mustoe TA et al (2005) International clinical recommendations on scar management. Plast Reconstr Surgery 110: 560-571